To answer some questions.
Net hack is a roguelike game. This means it is a dungeon crawler rpg in which you fight monsters, do puzzles etc. The game is played from above with you able to move in the eight cardinal directions.
The major problem is that the game is a roguelike, that is all in game objects are displayed as ascii graphics, for example your character is an at sign, walls are bars and dashes etc.
The reason Roguelikes have never been listed on this site is that firstly they have been pretty much unplayable unless you have a braille display, since as Jason says, having your screen reader saying dash dash dash dash space dash at dash dash etc reading line by line is not very informative.
Secondly, Even with! a braille display, since most braille displays only show a line of 40 or 80 characters wide, and the entire net hack screen is something like 400 characters long by 200 lines down, you need to do rather insaaaaane! amounts of overviewing to get an idea of the environment around you, even using the direct look cursor which can be moved around and used to point at objects, thus making them a hell of a lot more difficult for blind people to play as opposed to sighted people who get an instant overview of the screen. Thus the games aren't exactly accessible.
There have however been movements in the development of Net hack and other rogue like games to make the main display, ie the text messages you get at the top of the screen give visually impaird players enough information to play without having to tangle with the ascii itself, and as Paxed said, these movements continue.
Whether indeed it is now possible to play without the ascii just by looking at the status line and using the look cursor I'm not sure, its something for people to try out.
personally, I actually think it would be helpful if people could get an idea of what type! of environmental structure they're in, ie, a room, a narrow corridor etc, rather than just how far away the walls are, since just saying the distance to the wall doesn't really say what your character is doing, likewise just saying there is a goblin 40 spaces northeast doesn't tell you whether the goblin has a direct line of attack to you.
As I said, though this is a movement which has continued throughout net hacks development, and might well get there in the future.
I can say I have myself had fun in the past playing Angband using the large graphic tiles and my screen reader in conjunction, so if net hack could! be made accessible without the ascii it'd be a great addition to the Vi gaming world, though whether that is possible with such an inherently spacial game I am not %100 certain.
With our dreaming and singing, Ceaseless and sorrowless we! The glory about us clinging Of the glorious futures we see,
Our souls with high music ringing; O men! It must ever be
That we dwell in our dreaming and singing, A little apart from ye. (Arthur O'Shaughnessy 1873.)