I think this is starting off really well, some of the ideas here are fun! Just watch for some things like when your character crouches, the screen flashes red for a second, some of the collision is a little wonky and sometimes there's some frame rate issues when there are too many moving things at once. It's nice to see a lot of boss variety but you could add some more mechanics to beat them other than just jumping on them. The animations are good too, you're adding a lot of life to them. Really promising for an alpha release. Keep going!