Art seems pretty good but the gameplay loop doesn't make for a very good platformer. It's playable, but only fun when you finish a part of a stage and get a checkpoint.
Hitboxes of objects and the slide of the character as it stops moving make the game a bit annoying, often leading to deaths where I think i'm safe as i let off of the movement keys for a moment, but the character suddenly dies.
There are points at which spikes come upward from of a tile under them, which has a wall on its side you can come up to, and spikes' hitbox makes it so touching the wall is deadly, when according to the visuals shouldn't be, which also makes for cheap and annoying deaths.
Quick respawn and checkpoint system are a good call, as it makes deaths less impactful and keeps the player in the game for longer. Jump is also fitting in the game, as it has fixed height. Not having a variable jump height in games is often considered a worse option, but here it helps out a lot.