This was fun! So much so I went all the way to the end! There's definitely a few levels that left me stumped for a while, but I'm impressed by the amount of levels you've managed to fit in, 20 is quite a lot!
I liked the heaven/hell presentation, and the jazzy music of the first levels was very very nice. I didn't like the heaven music as much, as I found it a bit repetitive, but the third and last music was again much better!
I'm quite impressed at how much you managed to get into this game to be honest, so well done!