Platforming feels very good and particle effects are great. It's a shame after the tutorial there is no actual levels. Music is also a very big plus. Even if you won't consider creating the full game, I think that just filling in a few levels to be able to jump around, shoot and dash (even without any big plot elements) could be a lot of fun. For the jam it is great.
For smoothness I'd also suggest making the slash animation faster (if not instant) as the fact that player character stops to attack feels a little clanky.