I think I found a small bug in the game. After fueling the fire, but before talking to it, you can still walk around freely. if you go through a door at that time, the music and the other final sequence stuff will be reset. After that you can still talk to the fire and get the a ending, but durin the whole ending sequence the background and music will be the same as before and the red filter thing won't be there, but the flames will still be falling.
Also, great game! I got endings A,B and C so far, but I'm trying to find the other ones.
Edit: I also noticed that if you fall through the platforms in the infinite thing, the entered sequence doesn't reset, so for example you can enter the "code" using just the lowest platforms, and then jump up to the top. It could be confusing if someone made a mistake in the code and then fell down to enter it again.
Edit 2: I got the D and E endings too, with both being... interesting, but in very different ways.