Star Clock is a purchasable stage in Piano Tiles 2. It's a remix adapted by Pi, and it consists of a modified La Campanella and the song Little Star. Although, the "Little Star part" is a bit more subtle and needs a bit of listening to pick out. It has the fastest starting speed in the entire game, being at a ludicrous 8.33 tiles per second or 500 tiles per minute. When you get 2 crowns, the it has many crazy speedy double tiles. It was considered as one of the hardest song in Piano Tiles 2. This makes Star Clock to be constantly brought up between Piano Tiles 2 players as the hardest song in the entire game. It is also considered to be one of the hardest songs to score three crowns on (only to be eclipsed by Christmas Rhapsody). To get the third crown, the player has to go through the whole song at a ridiculous speed of 9.73 tiles per second. After obtaining the third crown, the player will go through the song at approximately 11 tiles per second. The current world record is 2100 by EK.
Players (even veteran players) will have a hard time with Star Clock due to its high speed. Players will have to get comfortable with 8 tiles per second which may take days or even weeks. One reason is that, 8 tiles per second is rarely encountered in the game. The only times it really reaches 8 tiles per second is when getting a crown or crowns on certain songs like Hungarian Dance No. 5, or Fantaisie - Impromptu for example. They can also encounter this during the Master Challenge.
Players might also need to get used to dealing with double tiles at fast speeds. A good thing to practice this on, is Hungarian Dance No. 5.