Fun puzzle game! Some times the drop door opens when the level loads, so the box had already moved before pressing a button.
I'd also like a hint on your easter egg, I looked around and even broke the game at one level by jumping out of the map, LOL. Tried click on everything, tried dropping through floors that don't look like I should drop through them, tired looking down at every part of the game... blah! hint... thanks, lol