Ballistic Overkill, the 7-year game design evolution of an online FPS. From a browser-based F2P to premium on PC.

Ballistic Overkill is an online PvP FPS with a 7-year long story behind. From a game design perspective, we go through the very different platforms (browser-based to Steam) and monetization models (F2P to premium) that shaped it into what it is today.

"Back in 2010 Aquiris Game Studio worked with Unity Technologies on the official demo of Unity 3.0, the Unity Bootcamp. The demo was downloaded thousands of times and caught the attention of some publishers who were looking for a partner to produce a next generation free to play shooter for the browsers.

Starting from a prototype in 2011, after a few test versions and being named Critical Mass, Quantum Conflict, before finally being called Ballistic, the game was launched on Facebook as a free to play shooter. The ambition was to be the most accessible and easy to play shooter, a game that you could load and play in a matter of seconds.

However, after 2 years being operated on the browser and building a community of over 5M players, Facebook proved to be the wrong platform for such a core game, the audience just wasn’t right, neither the technology. The game was slowly sunset as we planned its return as a premium experience on Steam.

We wanted to stick with the concept of an accessible, affordable and easy to play shooter, that could run on any average PC, but at the same time provides a premium gameplay experience, where the only thing to worry about is clicking on Play and start Shooting.

With that in mind, we relaunched the game under the title Ballistic Overkill on Steam, as a premium game, which is currently in Early Access. The gameplay and graphics were totally revamped, and we hope to attract many FPS fans as well as new players to this fun genre that is usually too hardcore to play." -Mauricio Longoni, Founder and CEO at Aquiris Game Studios.

In this interview we had the opportunity to talk to the two main responsible persons for game design of both, the Free to Play and Premium versions of the project. We will dig into how the game evolved and was adapted to the different models and environments in which it was launched, from browser Free 2 Play to PC premium on Steam.

Can you talk about the early production stages of the game? What were the gameplay premises back when it was known as Critical Mass, then Quantum Conflict and eventually became Ballistic?

Arthur: Initially we simply wanted to make the best FPS we could at the time. The publisher we had back then simply wanted a F2P CoD/Counter-Strike FPS style game with RPG and progression elements... pretty much all over the place right? Our goals have always been to make a fast-paced action FPS that would run well on low-end machines and look sharp at the same time. We also had to make sure the technology running the game behind the scenes was lightweight and scalable so we could support hundreds of players on a single server at the same time. The art style back then was super simplistic, drawing a lot from the gritty and more serious games that dominated the market. That’s when the two factions were born, MFA and Smokes, as well as the whole basic premise of a conflict over a new energy source.

The first step to that was to create a proof of concept that would showcase our ability to create the game. You can watch some footage of our first ever playtest over here, this was an exciting moment for the entire company, we played the game we had been building for about three months of hard work from scratch. This first demo had about ten weapons, no classes or skills and featured Hollow as the only map available. So Hollow is the single oldest relic of this initial version of the game that remains, that and the bullet marks I guess, everything else has been remade and replaced.

How was the evolution from those first prototypes that were inspired in Call of Duty and Counter Strike to the point when the game started to have a stronger personality? 

Arthur: With that playable proof of concept we jumped right into production. The first order of business was to add more content (levels and weapons), and add a F2P economy model. Our best estimates at the time where that we would deliver a full game in roughly six months and of course that didn’t happen. We kept churning out levels and weapons at a steady pace, but all the tools to actually make a successful F2P game where not there: we had no progression systems, no real player account management and had no live-ops plan nor the staff to keep things running and develop the game at the same time.

The game did evolve however and we focused on what we knew best how to do: add more content, add more core gameplay features and game modes as well as polish everything to the best of our ability. At the end we were able to deliver a solid game experience and did something super risky to show our accomplishments: we decided to play our Alpha version live at Unite 11 to showcase our game and tech. Despite all the things that could’ve gone wrong (to list them would require another article) everything went smoothly and we got a big applause at the end.

Aside of the multiple loadouts setup, the class and skill system were two major differentials of the game. How that system was born and how was its evolution? 

Arthur: At this time we already had a solid FPS foundation for the game, what we lacked was the means to monetize it according to plan. We did not want to do weapon durability, energy systems or pay-to-win content, so we were treading uncharted territory as far as freemium shooters where. Our first plan was to map out the content we had in most plentiful and put price tags and make players grind for it, the result of that was the weapons tree.

We had all of the game’s weapons separated into five categories: Standard, Strike, Tactical, Marksman and Heavy weapons. Each category had their own perks and players were encouraged to collect all weapons of a specific category to unlock some special weapons. Each weapon could be mastered through use and would grow in performance the more you used it. That design quickly spawned a series of unlockable perks, bonuses and extra weapons that players could unlock by mastering all weapons of a single category. Players would grind out (or buy) credits to get all weapons, then use them until they were all grand mastered and finally unlock some gameplay bonuses. This was the first open beta of Ballistic on Facebook, namely the 1.0 version in 2012.

That quickly showed us that players loved these gameplay bonuses and we decided to make the leap and implement a proper skill system that would allow even greater freedom for our players and that is where the skill system was first born.

The game went through several iterations of skill systems, both in how players progressed and unlocked skills as to how the skills themselves behaved. The first iteration of the skill system mimicked the weapons separation in several categories and made it so players had the freedom to invest their skill points in any way they desired in a generic skill tree:

For the entirety of the game’s 2.0 lifecycle (most of 2012) players used these branching skill trees. They could invest their skill points in any skill, unlocking the golden ones after spending three skill points on the ones above it. Each tree was divided in their own concept – damage output; resistance; stealth and speed – and players had a lot of freedom to develop killer combinations of skills and weapons that would eventually become our class system. In a sense it was truly our players who created the classes for us, we just gave them names later!

Can you talk a bit about how the classes were created? What originated each one?

Arthur: Classes came in much later in the development cycle after the 2.0 version had run for a couple months. We had just gotten a wealth of new input and were ready to make Ballistic big. We spent a lot of time developing the 3.0 version that would bring the classes to Ballistic in 2013. With the game already running on browsers and released on Facebook we had the perfect opportunity to review it from the ground up. That’s when the name Ballistic was branded and the game received an art and design overhaul. The user interface was completely redesigned, classic maps like Sunnsquare Mall and Corporate Park where created and the classes were finally unveiled for our players.

As mentioned before, the classes came up from the most popular builds players used from our skill system: some people played with the assassin skill and sub-machineguns for speed and close-quarters combat – that became the Shadow – others built a shotgun/submachine gun combo using the skill true grit (that allowed an SMG as a secondary weapon) with damage bonuses and they build became the Berserker. Every other class in the game came from combinations of skills and weapons that our players made famous (or infamous) by using our skill system.

Below are the sketches I did on a week where me and some other developers where off-site with a single task: to birth the concept of what would be Ballistic 3.0. It's interesting to see how recognizable some of these classes are even on these rough sketches, after several iterations, concepts, art passes and design reviews, you can still identify each and every core class from the concept ones below.

Can you detail the most relevant changes each of those classes went through during the F2P era? Also I see eight classes when we have seven now, seems Metalhead was removed, why?

Arthur: Yeah that guy quickly went to the chopping block as we already had enough “mid-range AR guys” in with the Vanguard and Pro (who later became the Marksman). All the classes went through a lot of iteration, both on their look and personality as to their role and weapon arsenal. You can see that we had several versions for each and even then they went through quite a lot of changes.

The class image concepts were also of great importance to us, since these where the most iconic of Ballistic's features and what draws players to the game. They went through several iterations until we were happy with them. It was a very rewarding process to get to see those 5-minute sketches become full characters over time and even better once they were in-game and playable!

What about the weapons of the game how are they created?

Arthur: Developing weapons for the game has always been fun. The game arsenal benefits from years of development and research, such as that at one point in the game we were starting to run out of weapons to create and had to really do our homework to find unique new guns to add to the game. We initially draw inspiration from other games and modern military but also from movies and comic books.

The large weapon collection grew from the necessity to have loads of content for players to collect and became especially important when we wanted classes to have a unique gun collection. Each weapon is researched to find new and unique characteristics to offer players maximum options. Things like fire modes, attachment options, interesting mechanics (like the Tank’s Mammoth, a shotgun shell loaded revolver). Every weapon that we place in the game came from research to create unique guns, like on the example below where I made specific requests for the creation of the weapon and all of its attachments.

On top of that we wanted Ballistic to offer some unique and signature guns. These have been custom-made for the game and went through a lot of iteration to bring the near-future universe of Ballistic Overkill to life like the Haunter below.

Ballistic’s weapon selection is a big appeal of the game and our goal with them is to allow players to find a weapon they love no matter how they would like to play. Add a ton of collectible skins on top of that and you have a vast arsenal to enjoy!

The Ballistic Overkill Era

What were the main hurdles from the game design aspect when you started working with the first versions of Ballistic Overkill? Could you detail and explain which were the major ones and how did you get through them?

Lucas Zanenga (Game Designer): The biggest challenge right from the start was understanding how everything worked. Ballistic is a project that was ongoing for several years and took many forms. This means that there was a lot of outdated stuff in code and documentation. Some things weren’t even used anymore. Finding out which features work and which are deprecated was the biggest challenge.

In regards to getting through it, I think that’s the kind of situation where the only solution is a lot of work and time. You have to dive deep. Test things out. After a few weeks you start to develop a “feel” for the project and things start to click more quickly. A tip that I can give is documenting your finds. Send emails to yourself, make a personal trello board or even regular docs. It’s important to keep track of your progress. You can be sure that, eventually, you’ll need something and won’t remember where it was or how it worked. Be ready for that.

It’s definitely a little intimidating in the beginning, though. I remember some colleagues reactions when I was testing some things in the aiming system, which were basically “Oh boy.” or a moment of silence followed by “Good luck.”.

What was the aspect of Ballistic Overkill redesign that you liked the most and why?

Zanenga: I love that all F2P mechanics are gone. There’s no temporary weapons or buffs that can make you objectively better than an opponent because you had the currency to buy it. In that sense, Overkill is much more fair than Ballistic F2P. Of course, there’s the lag issue, but outside of that, if you were killed, you got outplayed.

The other thing that I really like is the new skill system. It is basically a perk system. You can choose 2 skills of your skill pool. Players already start with 2 skills unlocked and equipped (default loadout). Leveling up unlocks new skills to the pool. That’s it. 

New Skill System

In the past, we had a skill tree. Players could level up and assign points to skills, climbing up the tree until the later final skills (which were, by far, the most powerful ones).

Image 2 - Old system Skill Tree

The old system brings 2 main problems:

1 - It’s unfair.
Veteran players will have a better, more upgraded character than newbies. Plain and simple.
The new skill system removes that completely (assuming that most skills are evenly balanced).

2 - Changes require extra work
Let’s say we want to add a new skill to each class. In the old system, we would have to:
1 - Make the skill
2 - Test the new skill with existing skills (lots) to search for bugs
3 - Figure out where to put it in the tree
4 - Make sure that the player can reach that skill
5 - Make sure that builds affected don’t become too powerful or too weak
6 - If required, reset the skill trees of players to remove inconsistencies
Players will probably take a few minutes to remake their own builds (not only do they have to choose all skills again, but the new skill changed the tree itself, so old builds might not work)
If they play without assigning skills they become underpowered

In comparison, here’s the same steps for the new skill system.
1 - Make the skill
2 - Test the new skill with existing skills (few) to search for bugs
3 - Make sure that builds affected don’t become too powerful or too weak
4 - If required, reset loadouts of players to remove inconsistencies
Players can remake their own builds in seconds
If they play without assigning skills, the default skills make so they don’t have a distinct disadvantage

As you can see, the new process not only reduces the amount of steps, but it makes some steps significantly faster and/or less of a hurdle to players.

Any difficulties related to the balancing process of weapons?

Zanenga: Not a difficulty per se, but the most important thing that I felt was necessary right from the start was creating a new set of tools for balancing. Ballistic F2P was balanced using excel sheets and exporting them to Unity, but that process was too slow and entirely not visual. We had a “playground” scene where you were supposed to test stuff, but there weren’t any real testing tools in it. Before I entered Aquiris I was an indie developer, so I knew my way around the engine and how to code. I had just gotten into the project and didn’t want to bother any of the programmers, so I decided to try my hand at create the tools myself.

What I did was find all of the weapon datas inside the engine and work with those files directly in real time. Now you could enter the playground, press a button and your weapon would fire faster or have a slower reload time. I also made an UI showing current attribute values (damage, rate of fire, reload time, accuracy, headshot damage, ...) and a lot of more detailed information based on those (Raw DPS, DPS considering reload time, damage at current range). This scene was certainly one of the most powerful tools created during the development and it saved me countless hours of time.

Playground Screenshot

What about skills? How was the creation and balancing process?

Zanenga: Most of the time we used the old skills as reference to try to keep the “feel” of each class. In the tree system, you could have close to 10 skills active at once. In the new system there are 2. So each skill could now be up to 5 times as strong without it being a problem. This helped us making skills that are much more “build defining” while also allowing us to take out some of the lesser or more boring skills.

About balance, it was pretty straightforward. 
1 - Create the skill and test to see if it is works
Repeat until it’s working as intended
2 - Play some 1x1 duels to check for big balance issues.
By testing with as few people as possible and fixing the big issues first, we can save the time of everyone else on the team
These tests are can be done per skill
Smaller problems and fine tuning comes later in the process
3 - Play some regular matches to check for further balance issues
This test matches involved pretty much everyone on the team, so they are very cost heavy
Usually we would make those tests with a whole patch candidate, not just a skill change.
4 - Next patch is released. Check real match results and player feedback
Once we’ve tested internally, the only thing that we can do is put it live and check the results
If we find that a skill is too strong or too weak, further changes are made in the next patch
If those changes are urgent, we put a fix up a couple of days after the patch

What’s the logic behind the unlock order of the progression system? Are there any guidelines or is it basically random?

Zanenga: Well, of course it’s not random, hehe. The first step is finding out which weapons and skills will be the default ones. This is mostly based on what we want for the character. What classes of weapons by which that character will be recognized for. Once you figure out the type of weapon, you pick one that is not too hard to use, but effective. On skills, generally you seek ones that are simpler to take advantage of and not too reliant on player skills. Then, you pick the weapons and skills remaining and follow a similar logic.

Weapons and skills that require skill to use, but are very rewarding, tend to go towards the end. Simpler ones tend to be unlocked early. After that, it’s a matter of weapon distribution, preferably, in alternating weapon types. You wouldn’t normally want a shotgun to be unlocked right after another right? The player just unlocked that! We want him to use it!

Which one was the weapon that represented a harder challenge to balance and why?

Zanenga: There’s not a single weapon that was harder than the others, but there are definitely weapon classes that are harder to balance. Shotguns and grenade launchers for example. The problem with those weapons is that they tend to be either too powerful or too weak. It’s hard to get it just right. Grenade Launchers are especially problematic in Ballistic Overkill because of the way the game mechanics work. 

For example, we have barriers in bases to avoid players from dying just after spawning and for players to have a safe haven. Well, some players just like to take advantage of that and spam grenades from the spawn door, going right back to protection after shooting. What we did to combat that was making grenades explode instantly upon hitting anything. This way, it’s much harder to set those traps. It might not be the solution for every game, but it certainly was a good one for us. Especially because that also helped with a consistency problem involving grenades.

Can you explain more about the consistency issue that involved grenades?

Zanenga: Grenades in Ballistic are instanced locally in each client. This means that, when a player tosses a grenade, a copy of that grenade is created for each other player and physics calculations are made in each of those machines. In most situations, this is fine.

However, because of the nature of physics calculations and vast array of machines, it is possible that the forces affecting the grenades end up behaving differently. In those cases, you can see a situation where, in your machine, a grenade is clearly below a player. But in the opponent’s machine, it’s a few feet away. This kind of behaviour is very annoying and can cause misunderstandings or accusations.

Much like during the whole development, we didn’t have many programmers in the team. Refactoring the whole grenade system would take some time, so we decided to solve or lessen the issue with design instead. The solution was the one I mentioned earlier. With grenades exploding on contact, calculation errors became almost nonexistent. 

Which were the main challenges you faced due to the game coming from a F2P model to premium?

Zanenga: The main challenge definitely was managing the players expectations during this transition process. You see, going from Premium to F2P is quite common, however, the opposite is not true. Players aren’t used to that.  Not only that, but we had the problem of the port itself. Some players just didn’t understand the fact that most of the game needed to be remade almost from scratch. For them, it was as simple as “put the game as it was on F2P, but on Steam”. 

Communicating that we were doing our best, while trying to keep players engaged was a huge challenge. In the end, only the most hardcore Ballistic players remained. Only now we’re starting to see a new surge of players.

Is there a particular class you like to work on more than the rest? Why?

Zanenga: Humm. I never thought about that. My gut response would be Grenadier and Marksman. The reason being the variety of weapons and builds that those characters can have.

Characters like Vanguard, Tank and Wraith are defined by their roles in a match. Vanguard is the “all around guy”, Tank is the damage sponge and Wraith is the sniper. Berserker is in an interesting middle ground. He is the rushdown character, but he does have some interesting variety to him. Grenadier and Marksman, however, have even more.

Marksman has variety by design. He’s supposed to be the one that can take any situation with the right build. Never the best, but always relevant. And the Grenadier ended up having variety because of the difficulties around balancing grenade launchers.

You see, our current grenade system is not the best, so we nerfed grenade launchers a bit to avoid exploits. To compensate for that, we made so the other weapons of the Grenadier are viable and varied. This means that you can encounter a grenadier that uses a GL and something else. Or one that doesn’t use grenade launchers at all, instead focusing on regular grenade related buffs, SMGs, shotguns and pistols. That variation is something that I came to love about the class.

To which extent the game maps influenced the classes’ traits? If so, could you share some examples? Were new skills added to the game?

Zanenga: To be honest, those didn’t have such a great impact defining traits and skills. The most relevant variable here is ease of implementation.

Overkill had a small team during most of its development. This means that programming hours are extra valuable and we needed to choose wisely where to invest them. The skill implementation system already had a strong base coming from F2P. That base gave us a certain “range of skills” that we could do very easily. Any skill that was outside of that was only implemented if it was considered key for that class (for example, Tank’s Last Stand or Wraith’s invisibility).

What is your favorite map and why? Also favorite class/es and loadout/s?

Zanenga: My favorite map is probably either Overhead or Blackfield. What I like about Overhead is the different feel that the up floor and bridge cause. You have to deal with it. If you don’t you’re just not playing the map effectively. And Blackfield is a great map for Capture Point and Free For All. Very open, and yet, with a lot of places to hide.

In regards to classes, I go through phases. Sometimes I’m favoring one class, other times another. If you check my current progression, though, you can definitely see that Berserker and Marksman have some more levels than the rest of the bunch. So I guess that’s the answer.

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