Very fun game with beautiful art. The upgrades, especially the double jump, are quite significant, which is good. Well done!
To make this game even better, I think the clarity of the game should be improved. The timer bar should also be re-positioned somewhere more eye-catching. The placement of the platforms can use some adjustment as well. Some platforms are quite awkward to jump on and can get quite frustrating.
Overall, very good game. The fact that you managed to do all this on your own is even more impressive. Nice job!