List of underwater stages
- Cavern series (rare, partially)
- Seaside series (partially)
- Submarine series
- Desert series (rare, partially)
- Beach series (partially)
- Snowfield 9 (partially)
- Blood Lake
The water level within the Lake stage stays constant. Any space above the water level is open air and is coloured black; any space below the water level is water and is mostly coloured blue, except the water in Blood Lake, which is red in color. The percentage of the game screen below the water level is predefined as follows:
- Normal level: 56.25% (18 of 32 tiles)
- Boss level: 81.25% (26 of 32 tiles)
For partially underwater stages, water appears only in small pockets within the terrain, and is shallow.
- Friction of water is higher than air, therefore:
- Characters and dead character parts that are flung decelerate faster.
- The effect of gravity is lessened (i.e. characters fall slower).
- Characters swim rather than walk when auto move is on.
- Characters can swim faster than they can walk.
- Characters will not suffocate without air, unlike those in Irritation Stickman.
- Underwater, characters can attack even when not standing on the ground.
- Projectiles and falling items retain the same physics underwater as with open air.
- All weapons work in water (including fire type weapons and iron-related weapons).
- All species can enter the water.
- Fishes and Eels (except flying eels) are the only species which can not permanently leave the water. All other species (even Bats) behave exactly the same underwater and above the water. For example, if Snakes enter the water, they will not swim, but will jump like usual.