Very well made and thorough game, looks professional as they come. I would almost give 5 across the board but there is always room to improve on things (can't think of anything specific at the moment though). I had a very hard time with the later levels, but I think the difficulty scaling was appropriate and I always like a good challenge. I didn't try adding my own music but it is very cool that that's an option. Altogether very solid game I had a lot of fun.