Agree with others that the mix of 2D and 3D is quite cool. The art could certainly use a second pass because there are a lot of conflicting styles going on, but I think if you really leaned into that combination of 2D and 3D you could end up in a very cool and unique spot stylistically.
The attack/jump/double jump thing was a cool idea, although I had some trouble getting it to work properly...? I'm intrigued by the thought process with that, and how it would look in a full game.
In fact, I would say that in its entirety this game has me very interested in what it would be like expanded and refined. Overall, good work!