Amazing, I had a game idea some time ago with doors and infinite worlds exploration but it didn't work out, so it was nice to see your game. Your approach was really unique and atmosphere was awesome!
I would suggest having some indication where will door lead, like arrows or -x or +y above the door, or something like that. Even tough i got it latter, it was quite stressful to play with time on your head :D
And if possible some indication if that door will lead to green or blue room, i know that there was a minimap, but I felt like there was no time to look a it and then try to figure out where should i go. So, overall my suggestions are just addition of clearer indication which would help players to not feel overwhelmed. But it is just my opinion since I am not that great at these games, other player might not agree with me.
Overall, idea was unique and whole game play was really polished. Good job for a very strong entry!