Impressive work! Everything works great together, visuals, sound effects, the very well written backstory and of course the very nice level design. It was a lot of fun to play!
The tile-by-tile explosions are nice, though after a while they slow down the gameplay quite a bit, especially in levels with more than one flamethrower. Maybe the flamethrowers could all fire at the same time to speed it up (I was once grilled by the first flamethrower but still had to wait for the other 2 before the gameover).
I'll definitely be digging into the source code of this one to see how you implemented all this :)