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Dodge Roll's Dave Crooks reveals how the studio has polished its bullet hell dungeon crawler Enter the Dungeon and revised its design to create spin-off dungeon climber Exit the Dungeon.

Diego Arguello, Contributor

May 5, 2020

11 Min Read

Dodge Roll has been iterating on the Enter the Gungeon property ever since its 2016 launch, releasing an array of content updates right until last year.

Now, along with a physical arcade cabinet for Enter the Gungeon: House of the Gundead that is currently in co-development with Griffin Aerotech, Exit the Gungeon is the latest version of the series, introducing itself as a spin-off dungeon climber.

Players have to command the original crew of characters and escape from the crumbling dungeon, making use of elevators while shooting everything in sight and dodging dozens of projectiles at once. While it certainly remains familiar to veterans of the series, Exit the Gungeon is quite different. It has a 2D perspective, weapons are randomly switched after a matter of seconds, and dodging can now be done in all four directions.

Bullet hell Gungeon

Games like Downwell and Shovel Knight Dig immediately come to mind as a point of comparison at first glance, but as game designer Dave Crooks tells Gamasutra, there’s a mix of both retro and modern influences at Exit the Gungeon's core.

“It started closer to a hybrid between Super Crate Box and shoot ‘em ups like The Raiden Project than Enter the Gungeon. It later incorporated more and more features from Gungeon, becoming a more ‘traditional’ bullet hell game, and Downwell was a touchstone for us in terms of level flow and game speed,” he says. This touchstone arrived later in development, as the first playable version was made by Jaewon Yoo from Singlecore Games, who then continued to co-develop the game with the team.

Crooks says Enter the Gungeon always carried the bullet hell DNA, but the top-down perspective, along with the traversal and collision systems never fully showcased the signature projectile claustrophobia of games like Ikaruga or the Touhou series. Exit the Gungeon is different in this regard, finding a new foundation to build upon thanks to its 2D perspective, along with several design tweaks.

Exit the Gungeon presents a more confined play space in the elevators, and the boss encounters have faster, more dense bullet patterns,” he continues. “For this to work, we took another page from bullet hell games, reducing the hitboxes of the players and the enemy bullets to allow for more overlap before a hit is detected. In Enter the Gungeon the hit detection was pixel perfect, though many projectiles had custom offsets, which we thought was necessary to make anything that looked like it hit actually hit.

"But the reality is that at the speed these projectiles travel, having a circle collider in the center provides nearly the exact same user experience with drastically less CPU demand. It is the only reason Exit can run on a phone, and why Enter likely never will.”

Learning how to do things more efficiently in general was the result of the shift to side-scroll view, but the real challenge was gravity, something that most bullet hell games don’t have. Along with the regular dodge that can be done either forward or backwards, players can also dodge upwards (a movement called Ascending Dodge Roll) and descend from platforms.

Crooks mentions that a jetpack in every level would have solved this, but its addition would have felt against the Dodge Roll from its predecessor. “It also didn’t make sense to us to have the player vulnerable during an ascending dodge roll when they have much less control than when they are on the ground, which is why we leaned into the rule of ‘if the player is in the air, they are invulnerable.’”

Unexpected scope

Despite the premise of being a spin-off of a much more complex game, scope ended up being bigger than expected. One of the elements that helps to portray this are elevators, their careful planning behind helping not only to live true to the higher focus on shoot ‘em up traditions, but also to keep spaces confined. This, initially, was expected to limit the scope of the game than anything else.

“We didn’t want to dive right back into another huge game. Enter the Gungeon was in development for five years, including post-launch updates. To preserve our own sanity we intentionally ‘scoped down’. I certainly believe that Gungeon could work well as a metroidvania style game, or something like Mega Man or Shovel Knight, but I think we would have been more tempted to go bigger than we had the energy for. Elevators and the arcade shoot ‘em up arcade framing kept the scope smaller, but it is still three times bigger than we planned. That being said, we would like to make a platformer at some point though…”

Confining players in small areas went along perfectly with the concept of elevators, taking the protagonists higher and closer to the surface in short segments. These are divided on a number of shifting stages, which end with a boss fight and have an intermission in the shop where you can buy supplies before the next level. As in Enter the Gungeon, you will also come across characters to unlock (if you previously purchased a key for their cell), which will then reappear in the hub.

But the team faced a problem early on. No matter which character you chose, everyone had the same set of elevators. From the beginning, Dodge Roll wanted to add meaningful variation between them, not just a background change. In its predecessor, the difference between characters was always intentionally minimal, as they didn’t want to limit boss encounters or had to re-design them for each one of them, and variation appeared during the ending scenarios instead.

“This had a very meaningful endgame, and replayability, impact on the game and the gameplay, and fit very nicely with the lore, but the problem is that Enter the Gungeon is, and was even more so at the time of release, a fairly difficult game,” Crooks tells Gamasutra.

“Today, four years after launch, only 18 percent of players have done the steps necessary to access a character’s ending scenario, let alone completed one of them. I don’t believe that ‘hidden content is wasted content’ by any means, but these scenarios were easily the most complicated things in the game to build, and more than 80 percent of players never saw them! So, as a reflection of the variety those character-specific sequences provided, we decided to make the elevators (largely) unique to each character.”

This approach also gave them room to play around their attitudes and backstories, tailoring the elevator sets accordingly. For The Pilot, this means riding on balloons, using a jetpack, or even piloting an elevator while dodging hazards, each one of them related to flying. If you pick up The Convict, you’ll find yourself in a prison riot, and even a side-scrolling section where you’re on the run from a moving wall of death. Elevators are the default type of scenarios, but there’s always variation around the 2D space and general movement.

Escaping the “mobile game” spectrum

Exit the Gungeon first launched as a timed exclusive for Apple Arcade back in September, only recently arriving to Steam and PlayStation 4 under a 2.0 treatment. One problem that Dodge Roll wasn’t expecting made itself present in the game’s presentation. Some Enter the Gungeon players came to the conclusion that the seemingly limited scope, along with the randomized gun switching mechanic, were a byproduct of releasing the game with mobile devices and touch controls in mind.

Crooks calls this a “somewhat frustrating experience for a number of reasons, but also an educational one”, arguing first and foremost that the weapon randomization idea came up as a way to address a number of design goals.

One of the goals covered the wish to emulate the game loop of an arcade shoot ‘em up or bullet hell game by asking players to collect power ups (in this case combo levels) without getting hit to become more powerful (through stronger weapons based on combo level), which reset on taking damage. In addition, this also helped to avoid dealing with ammo scarcity. Crooks explains that ammunition in games can often be either so abundant that it becomes meaningless, or so scarce that players never get to use the “good” weapons.

“Games often have a behind-the-scenes system to make sure there is enough ammo spawning in the world, including Enter the Gungeon, but these systems are very quickly datamined and reverse engineered by savvy players to ‘game the system’ and that ends up creating an ‘optimal’ way to play that has sub-optimal and often boring player behavior influences,” he continues. “That was a constant tug of war while working on Enter the Gungeon, which made ten times more difficult to account for in a procedurally generated game that locks the players in rooms. The gun switching allowed for an easy explanation for infinite ammo, and therefore no need to deal with scarcity.”

The initial heavy influence from Super Crate Box had players collecting ammo crates to increase their combo, which also caused their weapon to change, but it was modified to not be regarded as a too similar influence. In the end, gun switching made sense around the Gungeon universe, recalling to “Blessed” runs where the sorceress used a blessing on your weapon causing it to change randomly. Exit the Gungeon’s rules for switching “are nearly identical”, as is the timing of the switches.

When Exit the Gungeon released on Apple Arcade, it did so with full controller support, as well as support for mac OS. According to the developer, primarily designing the game with touch controls in mind was never in mind - gun switching was a fundamente mechanic in the game before the team even considered releasing it on mobile devices, and the only demand came from implementing a functional touch control scheme. Although they benefited from the reduced input complexity when they set about the mobile version, the foundational concept of the game was to make a streamlined game in a much faster manner than Enter the Gungeon.

“It has been said for years that ‘mobile games are the new arcade games’. Hell, I saw a full-sized custom Crossy Road machine in an arcade a few months ago, and I know Temple Run, Flappy Bird and Candy Crush all have arcade machines. Many design paradigms used to make an effective game in either space have a lot of overlap; simple controls, hard to master, seek revenue through small but hopefully continuous transactions," said Crooks. "I am not surprised that some Gungeon fans were rubbed a bit raw when we announced that Exit the Gungeon had an exclusivity period to Apple Arcade, which included a mobile version. Nor am I surprised that they were upset that the game was less of a roguelike than Enter the Gungeon, and more pure action. What I am a bit surprised by is a common assumption that we wouldn’t have made a game like this without the need to make a mobile version for Apple Arcade. When we announced that we were stopping further development on Enter the Gungeon, we said we wanted to make something new and smaller, and Dodge Roll has always worn our shoot ‘em up influence on our sleeve.”

Leaning into player choice was one of the valuable lessons that came from the development of Exit the Gungeon, finding out how critical that can be to the dungeon crawler experience in many players’ eyes. A lot of space or complex input aren’t necessary to support fast-paced action on screen, rewarding the player with meaningful decisions. Working in action elements can be great for some players, but preserving the “dungeon” crawler feel is, as Crooks argues, demonstrably less about control and more about choice.

“The negativity that the term ‘mobile game’ can stir is frustrating in-and-of itself, but even then Exit the Gungeon had its foundation elsewhere,” he concludes. “We learned some painful but valuable lessons in presentation, player expectation, knowing your audience, and IP management. I hope that any other developer that reads this can derive something useful from it, should they ever be in a position to launch a spin-off of a ‘core’ game on mobile.”

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