Co-op i assume
The game is best played on co-op.
Too bad i can only do local splitscreen co-op

Bashing splitscreen for a few hours (level 10+), so far so good. I must say playing alone must be some what boring, cuz soloing harder enemies is like suicide, but with 2+ players, it becomes challenging and fun. Weapon plays a major role in the game, good weapon = pwn4g3.