OK, thanks. I was able to get past the cube by maintaining everything in the right-side-up direction, before the dungeon automatically reset. It's not clear to me whether I was running out of time (that's a bit aggressive), or whether the game got confused, especially because after some flips and rotations the sprite's sword began coming out of him in a direction he was not facing (either evil or a bug). I was using the latest Mac version. Anyway, your hint helped me get through, thanks.