Art style is magnificent, mechanics somewhat less so.
A slower encroaching plague/fire would provide three major benefits: One, the ability for the player to process the story better, two, to allow there to be more complex movement and mechanics, and three, to allow the encroaching threat to build a little bit more before grabbing the player. Keeping tension high is important, and the fire instantly killing the player takes away from that somewhat. Perhaps it's a Dino Run situation where the entire screen needs to be engulfed before it's game over?
It's not entirely clear what does and doesn't count as material will block your movements, which takes away from the 'think quickly' aspect somewhat. Discerning dead ends ahead of time is hard, and the encroaching fire doesn't leave room for error.
Design is good, controls are responsive, well done on that part. Good concept, good design, needs some tweaks- such as a more suspenseful, dangerous sense in the music.