I got it, but I can't go past 1 and 2
I'm gonna repost some hints I told someone else here...
Now try to put two and two together!
Already got the first door done, 2 is the fucking hardest.
Put the text on the background of door 2's room (/f29ua1.png) at the end of your catbox link.
P.S: If you give up, go to the Incredibox wiki and check the gallery.