The co-op hook is that each player controls a blob and by pressing a button one of them becomes big and the other one small and vice versa. The small blob can jump high and far and can get into small spaces, but the big blob is heavier, can move larger boxes and can stand in deeper water and not die. It can also grab the little blob and fling it up and around to reach far and high places.

The game has its moments and the level design is not bad. The puzzles are not too hard and it requires coordination between both players.

However, the characters control like crap. The main culprit is the grab mechanic which is extremely unforgiving. So expect to see the grab animation while what you need to grab goes right trough the character model over and over again. This is bad enough for an average player, who can eventually compensate. But put that into the hands of someone with not a lot of experience of coordination with a controller (my girlfriend) and the game it's almost unplayable.