Great game... for people who like rogue likes 😝.
I tested with my commodore pc10-III, it has Nec v20 and can run in 4,77/~8/~9Mhz. For graphics I've installed for testing genoa superega card.
Game is definitely playable... bit sluggish few times while exploring message about npc battles got lost because keys for movement were already pressed when the notification came.
What I didn't like is not the game but the genre.. for example when I died I had over 4000 gold but nowhere to use the gold.
Would be nice if there were taverns to use the money, rest and re-equip, and travel between floors, doing missions for example destroying portals for tavern owners or temples, but that's not of course scope of this game.
Btw is there version of nethack that would run on nec v20?

Thank you for the feedback Kekkula! You'll be happy to hear that one of the next updates will involve what I call static levels, set in stone levels with things like towns with new NPCs, non-destructable buildings, etc. So hopefully you'll have some more changes to spend all that money! Missions / Quests is an interesting idea too, not one that I had thought of but I'll definitely play with the idea in my head.

I've had the same thing happen to me where i mistakenly cancel out of a message box because I've been playing very quickly. I was considering adding a short message queue system so you could hit something like M to see the last 10 messages.

You're welcome.
I don't know the limits of your engine or your skills so I just throw ideas... I'm not a programmer.
Message queue system or some specific key like spacebar to be pushed to make the message dissappear would be nice.

For the portals how about hiding them to hidden rooms where monsters would break out. Now that you have adlib music the ambient music could have humming in it if there are active portals still on level 🤷‍♂️

I've been playing with trying to get Adlib music playing during the gameplay, I haven't cracked that one yet because you still have to use commands to push the music on a note by note basis and there is no multithreading on these old systems. I have a few broken experimental builds that try to create a rudimentary time sharing scheme to play music and poll for input but so far they've been pretty unplayable. I've been meaning to scour ebay for more vintage game development books to find the lost arts of squeaking every last bit of performance out of the original PC hardware.

If anyone has any books they think are great fits for the era please let me know!

I hadn't considered the idea of exclusively putting generators into hidden rooms, I'll have to play around with that concept. Little hidden pockets of monsters could be a fun idea. I think you'd be very unlikely to find those rooms before all the monsters had generated and the generator had popped so that might take a somewhat big re-think of the generators. All of the new systems are things I spent a lot of time playing with but I think a lot of them need some tweaking to make sure they're a fun balance of risk / reward and still give the player maximum agency to decide how they want to proceed through the dungeon.