Rating issues
The game features mild and non-realistic violence towards human-like characters. Aliens and humans shoot at each other with weapons like rockets and ray guns, with the protagonists flopping down to the floor with stars around their heads when they are defeated. There is then a short countdown before the character respawns. The majority of violence in the game is directed against the aliens, who will fall over or explode into mechanical pieces with a green splatter effect.
Other issues
The game features online playing capability which may involve real-time interaction with other players.