Really well-designed puzzles. I suggest adding some obstacles with timing/reaction involved like the spike goes underground for 2 seconds then appears for the next two or a long electric current covering horizontally or vertically. Also wish the palette/environment and soundtrack changed like every 5 levels or so.
Could have used some in game instructions for the shooting, got halfway through before I realized that I could shoot the shurikens and I already finished when I saw you can shoot upwards lol. Other than that the game is really good in what it tries to do with its mechanics, very easy to understand (other than what I mentioned earlier). Great job!