Madness Hydraulic.
Madness Hydraulic is an arena shooting game that's part of the Madness series of games. This game has just as many insane weapons as any other in the series, but it also has a unique feature - hydraulic arenas. You have to try to survive through waves and waves of enemies by killing each enemy that spawns using any means necessary, like using their own guns, all of this while fighting in an arena that sometimes moves around due to the hydraulic mechanics.