I had a great time playing this game ! You did this in 12 hours ?
The idea of a character that mirrors all your actions with a delay and helps you solve puzzles is a lot of fun. The levels increase in difficulty nicely, and when it ended I thought "oh already ?". Also the pixel art is nice.
The only thing "negative" I have to say is that using the mouse and the arrows was a bit tricky (on an azerty laptop and being right handed) and I wish there was a key to use the shield instead of right clicking. But like, really good job !