Very cool idea! Although In my view, this game is somehow too difficult. I am a modern Tetris player, with sprint sub 40s in Jstris and ranked around SS~U in Tetr.io tetra league. However, I can only pass the first two level of 40 lines in this game.
The hardest part is locking, as soon as the tetrominoes touch existing sands, it is getting locked. I think this can be relaxed in some ways:
- delay locking
- when the touched sands are not connected to the floor, never locking.
- when the touched sands are in movement, the delay time is longer
Also, the end condition should be relaxed. Currently, the game is over when any part of the locked tetrimino is out of screen. I think this can relaxed to when all the tetrimino is out of screen.