Thanks guys, I appreciate the comments

My only (small) complaint is it seems to lack a sense of advancement. What I mean to say is, I can be stuck on a really hard puzzle for a while, then the next level turns out to be really easy. The difficulty skips around rather than ramping up.
Actually, that's sorta what I was going for! I find for me that a lot of puzzle games just get harder and harder until eventually you hit a wall and you don't want to play anymore - so I was trying to keep the difficulty a little uneven so the player wouldn't get demotivated... The idea was that though the game does get harder as you go on, the base difficulty never goes too high. Relatively hard levels are thrown in from time to time throughout the game to keep things interesting, with the easy levels that follow a reward for solving a hard level.
At least, that's what I was trying to do

The second level is harder than the third on average, which wasn't really intended, and there are definitely a few levels out of place thanks to last minute tweaking

This game made my brain hurt. But in a cool way. And I found a glitch, like Benza's: I was falling very fast, and at the same time hit (and went through) some switched-off blocks and the switch that switched them on. So they turned on and I got stuck inside them.
Sorry about that

I'll fix it next time I update the game...