Here is the link to the RetroChallenge to see the results of this year's challenge:
Fixed a problem with moving objects. There are two unused rooms, 21 and 22. I send anything you are carrying, or dragons that are killed, to room 21. You could think of it as the Valhalla room. However, there is another room that does not appear, room 22. When randomly moving objects you have to avoid sending anything to room 21 (Valhalla), room 5 (the secret room) and room 22. I hadn't included code to avoid sending things to room 22, so occasionally items and dragons would go missing, at least for a time, from the accessible spaces of the map.
In making these changes, I also changed the moving object routine to avoid moving objects placed in the micro dot room and the room where the chalice is initially placed. This means that both of these items stay put and don't get moved around. But now, once they are moved from their starting rooms, they are able to be moved by the bat like any other object. In other words, these objects themselves used to be off limits for moving, but now it's just the rooms they are placed in that don't allow movement of items in them.
I had also forgotten to prevent dragons from being selected when the bat was randomly moving things, so they could be brought back to life after being sent to Valhalla (room 21). Now items in room 21 are not allowed to be selected for random moving. This includes dead dragons, but it also includes the item being carried, so I was actually able to simplify the selection routine. It just excludes items in room 21, and things in the micro dot room and chalice room.
Finally, I also fixed the map in the White Castle. Now you have to pay close attention to the map in order to find a way into the hidden section... and out again!