Fun. Feedback: the only thing I found confusing is that it's not clear that the first block that is blinking is a data block. Maybe if it started with no block

Fun. Feedback: the only thing I found confusing is that it's not clear that the first block that is blinking is a data block. Maybe if it started with no block selected, and the user has to press Enter/Space to begin the game at which point the first data block starts blinking. That would make it clearer. Reminds me of Sokoban.