I like the overall aesthetic, and especially the fire transitions! The gameplay is a little cryptic at some points, but you can understand it fairly easily...
I just had a question: are you doomed to not being able to finish the game if you don't collect the first blue firefly before crossing the gate that closes behind you...? Some clue would have helped, something saying you can collect these, because they can just look like decorative flying thingies if you don't know it... :)
But overall a vey nice one!