I loved this. I feel like I spent a lot of the time confused but I think I got to the end. Unless there is more than one ending. Really fun to play regardless though!
You're over half way through - use the doors to block out any interlopers. You can use the codes you know to get back to where you were quickly. Hope we get a part two!
Ack! I figured it was the end because it closes the game. I'll have to give it another shot. Thanks for letting me know I can shortcut everything with the codes I have!