It’s a neat concept but I think the execution could be faster. Possibly If the bullet could move quicker, and if firing again could cancel out the last attempt midway, and let you immediately try another path that would be an option to speed up play.
Something that lets you see the path of the last shot, and even a button to reset you to that position and aim, so you can build off the last attempt would be good. It’s difficult to work out a solution at the moment because the player needs to look away to see what the bullet does after firing - at least that was the case for me.
Or maybe a top down camera of the puzzle room could be displayed at the side, that lets you see the whole result of your shot from above could help.
If you have time, would love to hear what you think of my game; https://itch.io/jam/gmtk-2019/rate/461074