You do a ton of great work with visual flair! Screen shake after character death, particles on jumping, and the trail that follows the player add some really good feedback to every action the player can take in the game.
The platforming can be quite tricky though. This mostly comes down to how much it feels like I'm running on ice the whole time - precision platforming and acceleration, and especially deceleration, do not mix well.
The sound design works well. It's simple, snappy, and the music loop adds a lot of character without getting annoying even with its short looping duration.