It is really good! The base idea is just great, and the execution just as much.
The difficulty curve is a bit steep, and I ended up getting stuck, but that's normal for a jam, and expect my game to have similar issues (I'm also a bit impatient, so there's that).
It is a really fun, original and polished game.
Ah! You actually have to use the rook/castle to get the king past the spikes, and the pawn needs to get another use to get things in place. I should definitely have an easier level with the knight/horse beforehand, because having it be introduced ends up implying it's more important to the puzzle than it actually is.
