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.