That was nice.
Couple of things I'd change:
- Esc takes you out of full screen in the browser then you have to do it again to get the menu up - may be have another key option as well
- I noticed level 10 was open after i'd finished 7 (I think)
- The messages were overwriting themselves especially with the ESC to levels up which stayed when I had completed the level or if I needed to restart on being spiked.
- May be small thing but Id prefer my character to pop a bit and not be the same colour as the blocks as it would sometimes feel stuck when it wasnt
Good effort . Enjoyed it.