Really cool idea! love the concept and was satistying to figure out. The one thing I would change would be the way you place the beats. I think it would be way more comfortable to play if you used like a "paintbrush" kind of tool, and could select a beat, and click everywhere that beat is. Like for example, select kick, and be able to click where all the kicks should be. However that's a small critique, other than that, awesome game. Congrats!