This game is really sweet, haha! I saw you posted on my game comments that yours was similar, and yeah it's pretty crazy how we had such similar ideas. In terms of your game, I really liked how you started adding switches, blocks and other funny events like the flag falling from the sky. It really gave the game character which I loved. And there were so many levels, which was awesome!
Two critiques: I wished sometimes that I could've just clicked R to restart the level, instead of having to deplete my stack. I also got tripped up a few times when I accidentally jumped and lost part of my stack during a transition (and at the end too), I would have just been nice if movement was disabled during those transitions/end cutscene.
Overall, great work, and also very impressive considering you're a solo dev too, wow!!