While I was practicing today, some strange behavior happened in the block room in 7-6 (4th house). I had the Tenshi powerup, but all of a sudden I was unable to summon rocks. This happened a few times, and I was able to record the event.

https://drive.google.com/open?id=0B-lxFwygRehgbHMwVENjWTNacGs

It's possible that this only happened because I'm running the game through Wine. Has this happened to anyone else before?

That's not the only erratic behavior I've gotten in that room, though this is almost certainly a separate bug. I've managed to kill the cactus fairy in the top right in such a way that the cactus zipped through blocks to the left side of the stage. I haven't been able to replicate the zip, but it seems like it could be useful.