Yeah, I've noted the jump/walk buttons being a bit annoying like that; same for the lack of progression indicators. Thanks for the feedback!
As for the size upgrades, I've noticed the same issue. In general I don't *mind* the player being able to cheese some puzzles, but with full powerup set it gets a bit much. I'll probably try to either find a way to disallow that via puzzle design or tweak the numbers in a later update.