This was fun! If you don't mind me making a suggestion; Spawning at another door after going through one was a bit disorienting and made it harder to remember which door the item I'm currently carrying came from. Also if the first time you go through a new door it doesn't spawn an enemy so it gives the player time to get familiar with the doors before being chased.
This was a really fun take on the "What's behind the door" and is one of my favorites in terms of theme. And I had a lot of fun playing it. Great job!