Unangband, the raw gem...
Did you know that you can increase the damage of fire branded arrows by throwing a flask of oil onto the target?
Un is full of them, little details that give, in theory, the game a kind of life that is nowhere to be found in any *band. Too bad there are way way too many of them , so it is ultra hard to get into the game. I have played 5 or 6 characters to level35 and I still don't know which of the 3 or 4 instances of Bree I have to avoid at nights at all costs.
Too many options, too many things to look out for, resulting in playing takes forever. Especially with the new monster generation you can't just clear a level. Doing so might take an hour of careful planing. That is: If the features allow you to. Features... I don't like them in NPP where they are a minor danger/annoyance. And Un is so overfull of them, even lacking a normal dungeon more or less all the game. Did anyone ever try to play in those water dungeons?!? Seriously... Or those chasm ones? I guess one could disable the campaign, but that would take away half of what makes Un special, so I'd rather not do that. The campaign itself is a great idea... It is huge, I bet half of the levels have never seen an @.
So what does Unangband need?
Many of them. I can talk about how charging is too weak deeper down, with noone else playing, I could be right or just not good enough.
Get rid of the annoyances:
Allow going back the route you have taken for two ingame hours (say backtrack own footsteps) in all but a very few cases (entering lonely mountain should stay the way it is ...).
Get someone to draw a map of the campaign. Not the autogenerated one that, I think, Pete made, but a jpg one with descriptions. Heavy spoilers.
Offer some goodies:
Heng's Big home is a nice start. There is way more stuff I want to store than those 24 places can hold. Further, allow all ego item melee branding combos. Allow branding of Magic items. Remove penalties from ego boots. Yes this makes the game easier. The game is hard, it needs rewards to make it worth going for. Take Heng again as an example... Scrolls of Artifact creating... where are those in Un.. Scrolls of Magic item creating could be available too, and not deeper then ?acq.
The perfect variant, in my eyes is challenging to the max, but still very fast to play and very rewarding. In Heng there are two uniques that can actually stop the time! In Un, the generation of only deep monsters should be challenge enough alone...
Yes I know you hate color coded recall screens, but with all the new things, a well readable monster/feature recall is necessary to speed up the gameplay.