I have also noticed the following potential issues:
- "go to stairs" seems to path through unknown secret doors
- in DataFiles, I see a weapon corresponding to what the boss Ch. is wielding, so it appears that he should drop that weapon, but he does not
- it also seems that going to the entrance to the game after killing that boss should display a special message, but it did not do so for me
- I had no idea how to go through the gate in that boss room (I did go through it but I am not sure it was the indended way), and the following area seemed unwinnable without revive. The items that I think might be related are the "abyssal pearl" (which I had but it did not seem to do anything), and the aforementioned weapon (I see it gave resistance so maybe with two other quest items giving similar resistances it could make that area bearable)
- when I am killed by a monster while using a spiked shield, the game seems to display a message about the enemy being killed by the shield, and then a redundant message about me being killed, while revive shows that the enemy was not actually killed