Challenge your friends in Death-match, Last Man Standing, Shotgun Soccer or crown yourself king of the couch in the all-including Party Mode! All bullets will bounce off the walls, giving your friends no place to hide, but watch out since your bullets might end up biting you in the ass! There are 3 weapon types in the game. By default you carry a shotgun and every stage has two extra weapon pickups.

*The standard shotgun is good for spreading a load of bullets
trough the arena.
*The assault rifle fires a barrage of bullets in a straight line, but
bounce once.
*The sniper rifle fires a high velocity bullet that can still ricochet even
after piercing through another skull, creating a sort macabre
Billiards of Death.

There are 5 game modes to explore:
Deathmatch | Last One Standing | Shotgun Soccer | Head Soccer | Party Mode

The first two you probably already know. Shotgun Soccer and Head Soccer are literally soccer - but with shotguns.
Lastly there's the Party Mode, where you get to play all these modes in a tournament, combining all of the 8 arenas set in three locations.

*The Crackyard, the old town graveyard littered with chemical waste
and invaded by squatters.
*The Play Pit, a construction yard with tons of walls and building
materials to hide behind or bounce bullets off.
*HOME, a Scandinavian Furniture store! Not the best place to play
soccer as those hasty shoppers might run you over with their cars
to get to the best deals.

More details on the official game page of Trailer Trashers ...