There's gameplay, mostly of the discover and minor puzzle solving variety. Puzzles unlock Worms (which are your friends but don't seem to be playable or anything), there's one "major" puzzle per area of widely varying difficulty/type. Eyes are the primary "collectable", basically you just fly over the eyes (they're varying degrees of hidden) to "open" them, and there's a counter of current area/total eyes opened in the pause screen.
I have no idea what collecting all of them do, but it seems to be the only goal at this point. As mentioned, at least a few hours of gameplay so far.
Fair warning: the first area is rather confusing and leaves you to "solve" a "puzzle" by yourself. Just bump into things and you should be fine. Most puzzles are solved by bumping into things to see what they do.