The platforming mechanics felt really nice, and the audio and visuals are fun! I like that you have a built in leeway for the sword to cut the bullets (though it might be a little much since I noticed it immediately).
Going back through the level felt nice because the wall jump felt really smooth, but without enemies to fight while doing so, it was lackluster. My suggestion would be to build your levels to focus on the platforming/mobility more. In this demo you don't need the wall jump until the end, but it would be cool to climb up a wall, jump in the air, and slash an enemy in the back or something. Those kinds of moments are always real cool :)