A decent hack n'slash with decent length. Very shallow even though you can upgrade your different attributes and gain character-specific abilities. The levels are larger areas with many nooks and crannies to explore which leads to finding new weapons (close range and long range). There are 4 characters to choose from although the most difference comes from the special abilities which aren't that special. (added flame damage, electrical damage etc.)
Local coop is nice but I'd recommend online coop because the camera only follows player 1 and there will be parts where dividing up will result in unmanagable chaos and/or backtracking. There are different kinds of enemies but generally all you do in the levels is the same no matter how diverse they feel: Kill loads of monsters, help an NPC with something or protect them and also item hunts.
I'd say buy this in a sale and go in with very low expectations. The combat isn't deep and it all boils down to button mashing and building up massive combos. If you want to play single player, just forget this game it'll get boring really fast. Coop though is another story. The very definition of a bargain bin video game.