It's a decent platformer with a fair bit of issues that prevent it from feeling really great to play.
The art looks nice and well put together. The level design, while simple and easy to breeze past, serves it's purpose. I liked that, if all the levels are looked at together, it seems to build on itself both in art and the design slowly growing bigger, or in the case of the plants, just growing haha.
The jumping, as others have said, doesn't feel the greatest. I noticed that you can only jump again once the landing animation has finished, so it might be worth looking into whether the trigger to be able to jump again is only reset after the animation plays.
It's a bit frustrating to not be able to attack flying enemies while also in the air, but it does pose an interesting challenge to lead them into a position where you can hit them. It could be really cool to expand on this idea where attacking is more positional. It could add a bit of a puzzle element in the sense that you have to figure out the best place to attack each enemy if the game were to be expanded. Although it was frustrating that the enemies can still damage you even after you kill them and their death animation plays.
Also, I don't think attack works on controller, though it could have just been me or my controller that didn't work. The other inputs worked perfectly fine though.
Overall, good job on completing a game for the jam! My favorite part of the game was grouping up the enemies and slashing them all down together. That was satisfying!