Nice variation on Tetris! A few things that might help improve it:
- The play area is quite wide and makes for long duration games. A narrower level might work better?
- Some sort of feint grid behind the playing area to denote where the columns lie would be helpful. I sometimes dropped a shape and it missed the intended spot by 1 place.
- It's nice to have some 'slip time', that is being able to move left and right for a moment when the active piece has collided with something rather than just stopping as soon as you collide.
All the best with your revision!