Yeah, I noticed that two hours after the submission time. There are two types of variables (aside from bool, int, float, and string): normal and global. Usually, when the sprite carrier is destroyed or the scene is restarted/changed, the variables reset to their initial numbers. Global variables, on the other hand, are unaffected by the sprites or changed scenes, so they have to be reset manually. I remembered to reset the score but forgot to reset the lives and the speed counter, so the game got stuck once restarting the game to play again.
I already fixed this but I can't upload the new version until the GMKT Game Jam voting period ends. The only way to fix this at the moment would be to reset the page. Thanks anyways for playing!