Developing the Plague of Shadows expansion to Shovel Knight has been quite the tricky experience for us here at Yacht Club Games. We’ve never had the pleasure of continuously building new content for a complete, existing title before. When we pitched an all new playable boss campaign during the game’s Kickstarter, we were thinking of something small along the lines of Mega Man Powered Up: a simple character swap with a slight mobility change or a new ability between the boss characters. Of course, we wanted it to be fun and exciting…so we decided to go bigger!
One of the interesting challenges in this regard was creating a mobility set that really felt unique to the character of Plague Knight– a villainous alchemist with a love for explosives. We decided early on that the majority of the game would retain its initial level design and that the fun would instead come from new mobility which would make even the old levels feel entirely fresh. In order to achieve this goal, and stay true to the game’s inspiration, we knew we needed to create a mobility that felt truly at home on the NES!
The character Shovel Knight, of course, already has an NES mobility set! But his focus comes from the joy of simple NES controls. Whether it was dig-slashing or shovel dropping on enemies, Shovel Knight had a small number of action buttons which resulted in a set of solid, clear attack states! We thought we could bring Plague Knight in a different direction. Often in NES games, players would boot it up and wonder how to even move the character! Do you remember starting a new game like Castlevania only to discover hours later how to climb stairs or use a subweapon? The concepts being explored in games around that time were sometimes so new that there weren’t standards for how to jump, how to attack, etc. We hoped players would sit down with Plague Knight and be curious in the same way…enjoying the discovery of each button’s actions. We hoped they would learn a new way a character could move in a 2D world. Maybe something they’ve never played before – just like picking up a new game during the days of the NES. Something that was easy to learn but difficult to master over the course of the game. The fun would come in learning the character’s strengths and weaknesses, and using them to his or her advantage!
(Castlevania's manual even had clear instructions on how to hold the controller so players could be ready to both JUMP and ATTACK)
Laying down rules
All that said, we still were bound to the level design of Shovel Knight, so we had a few rules we had follow in order for the levels to work!
- Shovel Knight can jump ~4.5 tiles high.
- Shovel Knight can cross horizontal gaps ~4.5 tiles long.
- Shovel Knight can bounce off certain objects getting an additional height of ~4.5 tiles.
- Shovel Knight can dig through blocks horizontally.
- Shovel Knight can dig through blocks below him.
(Everything in Shovel Knight was built on a grid! The levels were tuned to his mobility!)
Those weren’t the only design restrictions we had though! We also had to find a way to be true to Plague Knight’s character. Here are some features we felt were important to highlight:
- Plague Knight is all about explosions!
- Plague Knight is a scientist that creates items through alchemy.
- Plague Knight is wild, maniacal, and dangerous!
- Plague Knight should feel like you’re controlling the character you saw in the original boss fight! (A few key components from his fight: lots of bombs, wild big jumping leaps, explosions everywhere! He generally feels out of control!)
(Many players are still wary when dueling Plague Knight!)
Building the Mobility
With all these rules in place, the next step was capturing his essence while allowing the level design to work. We started with our core mobility move – the burst:
As you can see, this combination attack (from the explosion!) and jump allows Plague Knight to cover a great distance in a small amount of time, but at the cost of some freedom of control. Once a horizontal burst is detonated, the player’s left and right input does very little to change it! This captures Plague Knight’s wild spirit, the seemingly out of control jumping in his boss fight, and gives the player the ability to cover many horizontal and vertical gaps that Shovel Knight could cover. It also can only be used by charging the attack button first…this means the player must really think ahead before committing to the action!
But the burst doesn’t cover everything we need. We don’t have a basic attack or jump! What if the player needs to cross a smaller gap or hit something slightly farther away…you wouldn’t want to force a wild jump on them. And the player still can’t cover enough height to match what Shovel Knight could achieve by bouncing off an enemy or object. So we still need to retain the game’s universal actions: running, jumping, and attacking.
For running, we decided to stick with a speed slightly slower than Shovel Knight. This slower speed allowed for a better contrast between just running and bursting. This helps make the burst feel that much more wild, while still having it be understandable.
Plague Knight has a double jump! We wanted Plague Knight to have a shorter jump than the springy Shovel Knight, and adding a double jump gave him more height so he could mount basic obstacles. It also allowed another layer of control. When combined with burst jumps, players can more accurately adjust where and how to land. Or they can even take advantage of the burst’s momentum to keep their faster momentum:
(The attack range sketched out!)
Attacking had to focus on bomb throwing like the boss fight. However, we had to find ways to limit the player so they couldn’t completely overwhelm enemies with bombs. On the ground, we went with a standard – a series of three short projectile throws:
The main gameplay balancing act here is how it completely stops the player’s momentum. While the ground throw trajectory is dependable, Plague is also slower on the ground. Stopping like this is dangerous because it can be difficult to get out of the way of an incoming enemy or attack. So it’s time then to take to the air!
In the air, the player throws the bomb near a 45 degree angle. These thrown bombs also plummet toward the ground at a much faster speed. This way, the player only has to focus on lining up the angle of their attack from above instead of worrying about leading their shots. While Shovel Knight’s ideal method of attack was to steadily and repeatedly bounce on top of an enemy, Plague Knight’s sweet spot is to line up an angle from above before rapidly letting a series of projectiles fly. This alternate style of attacking combined with the burst is what really gives the player a truly new mobility feel.
Notice the player also slows down when throwing bombs in the air. This was an important design element for two reasons. First, it provides a consistent way to control Plague’s air speed. Since the bomb bursts’s speed and arc is fixed, giving the player the ability to stop themselves or slow down was very important. Second, it makes it much easier to be accurate with the bomb as an attack, as the player can lock into the right place before unloading attacks on the same target. Without slowing down Plague, a lot of players would be showering an area with bombs rather than pin pointedly hitting their targets.
Don’t forget…there’s one more thing that makes Plague a little more risky. His knockback when damaged by enemies is much greater than Shovel Knight’s:
This was a conscious decision so as to make Plague seem that much scarier to control and to make the player re-think some enemy placements. It has one other benefit – since Plague Knight is a projectile focused character, being cleared far away from an enemy on hit helps guide the player to attack safely from a distance when retaliating.
But don’t worry, if you calmly charge your burst, or save your double jump, you can recover from any situation. No problem!
That’s it! Plague Knight has a lot more to him in terms of upgrades, armors, etc, but this covers the basics. Tomorrow we’ll be delving in to how to exploit the mobility and use all his tricks to your advantage, while explaining how these tricks arose from our iterative process.
We hope seeing our mobility design process and implementation helps fans and developers better understand what goes into building a unique movement and attack set for a character. There’s some stuff we didn’t cover…tiny things like turn speed, acceleration speed, attack delays, recovery times, and much more…see if you can figure out why we made the decisions based on what’s above! We can’t wait for everyone to get their hands on the crazy mobility and push it to its max. Let us know what you think!