I have to agree, failing a song on Geek seems to almost impossible, and the notes don't appear to be very related to the music at all. The songs, however, are anything but too long, 3 minutes is pretty short actually.
The big problem with #5 is that while the picture and hint easily point to a certain person, no spelling of its name appears to be the answer. And there is no other hint that would even give an idea what else you could be looking for.
Now level 18 is broken. If I move down all of a sudden all black fields turn red. It also seems as if the electricity stays off even if you have to restart the level. Be sure to test more properly before releasing in the future, both of these broken levels should be easily noticed when playtesting.
Okay, got the record time for size 3, size 4 and size 5 random puzzles now, time to go to bed. I might tackle size 6 tomorrow.
Level 28 is pretty damn hard, got totally stuck there.
The Spear throwing seems to be bugged somehow, and if there's some sort of action going on it's almost impossible to do anything when you have a spear in hand and you can't even drop it.