Such a polished game. I love the sound effect used for the robots. The music fits the theme too. The puzzles on the other hand looks challenging, although it is actually quite easy when you understand the mechanic. My suggestion, perhaps each character should have unique attribute like others have said, perhaps one of them moves slightly faster or floats in the air for a quick seconds before reaching the floor, idk, I'm sure you know better. Adding more obstacles beside the liquid acid and the thorn such as the platform disappearing or is moving would make the puzzle to be much more challenging and entertaining too. Animation for the acid liquid would be a nice touch as well. Above all, this is well polished game, well done!