Hey, I loved this a lot. The pixel art is amazing. I don't have a lot of serious criticism, but just a few little things: at the start, I almost quit out of frustration. That changed after I got a sense of the "item progression," which made me feel like I had a defined task to work towards. My suggested fix would be something like... disabling the timer drain when you're on the starting screen.
Also, tiny thing because it's all I can think to say, some coyote time would be lovely alongside the jump buffering you've already got :D