As my first runs I disliked the fact that you fall to an under room and just fall into a bunch of enemies without being able to do anything. Also the shooter enemies should have a little delay instead of shooting you instantly, you should be able to swing your katana in both directions when you are on a wall. And I really don't understand the purpose of exit a level, you restart a new fresh level with 20 bucks even if you had plenty of on the previous level that's frustrating a bit you can't try to get the 'personnal highscore'.
Overall I enjoyed the game pretty much, I was really surprised by the menu I though that was a static one. Great job !!