Wack a Mole
Wack the mole over and over again until you get tired. This took me around 4 hours. (You can now see the highscore)(also how is this on trending? I literally started 5 days ago)
I have an idea. Why don't you hold a variable for the amount of milliseconds to wait and each time, you decrease the variable by a few milliseconds so that it gets harder and harder each time!