Hi ! I tried your game.
The gameplay: The physics is extremely basic, with no acceleration. I would definitely suggest you to add inertia ! (meaning that the character won't stop directly if you release the direction button) There are multiple bugs/weird things; you can "climb" on every wall, you can't jump while you are a the top of a ladder, sometime you get hit by a mob, it flies away (because it died), but its hitbox won't deactivate so you basically fly away with the mob. And I think there are a lot of other physics issues because I played 5 minutes. The text tutorial is a bit useless but does not disturb the gameplay. The bouncing plants are a bit unintuitive (you have to bounce multiple times).
The Art: Quite nice ! The entities are cute (character, enemies and apples with shining effect), maybe the spikes are a bit too geometric.
My advice would be to focus on physics first ! Add a bit more complex physics, and removes those weird bugs ! But it is good to have already all those levels