interesting puzzle collection :)

that'd be a fun puzzle!

hmmm good idea, maybe we should have an auto-rotate that stops when you interact

Better than an automatic smooth continuous motion would be an "idle animation": after a few seconds swing the torus somewhat less than 45 degrees in a random direction and let it relax back into the original position. This suggests "the torus can move" without suggesting "the torus moves [only] in this specific way." You need contradict not just the user's intuition "Torus stationary" but much more importantly "Torus non-interactive."

Likewise, if someone thought the pieces couldn't be moved, you could idly wiggle the king pawn as a hint to pick it up.

Now, how anybody could look at a chess board and think the pieces were immovable, or look at a 3D torus render and think it was unrotatable, is beyond me. But if it's a real problem, I think idle animation is a good fix.

very neat. I'd say this is kinda on top of a torus, and more of a cylinder from the perspective of the Tetris pieces. not sure how you'd play on the surface of a torus, since you need to wrap around vertically too.

E.g the pieces from the rows you eliminate reappear at random at the top row.

ahha true, I forgot this was the case. we like the setup this way as it has rotational symmetry, which more naturally extends to supporting 3+ players