It was fun, I got 14390. I liked this take on a tetris-like game. It introduced a whole bunch of new considerations, and felt new to me. Especially at higher stacks, the instability also really came across/ I feel like the limited ability to steer the blocks in the air was also very fun, and allowed a bit more of a feeling of control while still maintaining the instability aspect. Great job!
Edit: I played a second round, and I actually quite like the ability to let some blocks fall without losing. It allows for fun things like using pieces to hammer other pieces into place, or to knock pieces off that aren't as flat so you have a more stable platform to build on. Currently at 21030!