The idea of changing your weight to solve puzzles is a fantastic concept! I did struggle a bit to understand exactly how the weight gets added to the player in every situation, though. I noticed that soaking up rainwater made me heavier, and standing near the lights (and out of water or in the sun) dried me up to make me lighter. But on the night levels, I couldn't quite figure out why I was getting heavier. Was it sweat from jumping and moving? I tried to test it but didn't quite get it. Nonetheless, this is a brilliant idea and you should definitely keep improving on it and release it someday!