I like how there is "no build up to the difficulty", so you just jump right into the fun, skipping any boring easy stuff. This way it's more fun when replaying to try to beat a highscore, and more fun when practicing, which makes it easy to improve and progress.
The difficulty is just right, it's not too hard or easy.
However, it's missing a leaderboard and I rather play with the arrow keys.
Another problem is that it should have an auto-restart or a way to restart by just pressing a keyboard key.
my high score is 28
now 37
now 51