Very nice and entertaining game!
I skipped a puzzle because my character jumped from some weird collision reaction, and you can skip most of the puzzles just by splitting through doors and absorbing from the other side. I think you also can hold objects heavier than you after you split.
Those are just small bugs though, the game itself is very fun! The puzzles are neat and simple but not dull. The controls are surprisingly intuitive for a game where you control so many characters! Really quite impressive, well done!