I like the visuals of this game, especially when the colors change the the sine wave becomes more prominent! I think you've got a good start to a game here. The only pieces of feedback I have for you at this point is I would speed up the pace of the game. Make the items show up more frequently and the sine wave start sooner. I would also challenge you for your next project to start adding sound effects as soon as you can. Even just a temporary beep because it's easier to replace a sound already implemented than go back and try to implement sound later. Sound is the most bang for your buck you can get when it comes to game feel and even a generic sound that doesn't quite fit is often better than silence.
Awesome job!