Good job.
The concept was good and it's fun to play, but there is too little room for error in gameplay. The game lags periodically which, when coupled with the incredibly slippery physics, makes the platformer element too difficult to be enjoyable. I checked the walkthrough on several levels only to find out I was doing it correctly, I just wasn't getting the timing right due to lag. If those elements are part of the puzzle, congratulations; I'll stick with games that respond the same way every time.
I want to see a sequel with less lag, improved physics, and more interactions with the boxmen. A built in tutorial would be better than, "Remember to experiment," as the puzzle should be, "How do I beat this level with these tools?" as opposed to, "What tools do I have?"
All in all, very fun. Nice work getting the front page, as well. Terrific third game; keep making more.