Each time you finish the loop you get 1 point. once you press space, it stops and the game ends.
Classical Piano is the hardest sound in the Sounds tab for beginners to use well. In so many of the projects in which that sound is used, it's a music track that plays the entire time the project is running- nonstop. Which results in a project that is mentally intolerable unless you mute in in some way, because you're playing the same identical, agonizing loop 6 times a minute! It's unfortunate.
