Atomic Ninjas

Atomic Ninjas is a video game developed by Czech company Grip Games. It is a Multiplayer Action 2½D platformer. It was released for PlayStation 3 and PlayStation Vita. Grip Games also plans to release Microsoft Windows and OS X versions.
The game focuses primarily on multi-player. Players can choose if they want to play it as split-screen or as an online game. The game also includes single-player. There are multiple modes such as deathmatch or capture the flag. Players can choose out of seven playable ninjas and seven arenas to play in.[2]

Players can’t kill each other in direct fight but have to push their enemy into a trap, which is part of an arena. There are also skills that you can upgrade[