Awesome game! The tutorial levels could use a little work.
Spoilers below
Level 2 didn't help me figure out that the doors had 2 sides, a yellow blast-proof side and a red blast-able side. What if the two doors were much bigger and right next to each other so the bomb hit both of them at once? Then the player could see in a single blast that one door vanishes and the other does not.
Level 3 I couldn't tell there was a hole in the ceiling, there's just way too much bloom. The walls are all white glare. The yellow bar seems to mean its next to a hole, that's un-intuitive tho. I kept trying to bomb between the two yellow bars thinking that was a doorway. Can you instead reuse the hole shape you used on the last level 
? Get rid of the solid yellow bars in all the levels since they seem to mean the same thing as blue blocks?