Ancient Domains of Mystery, or Ancient Domains of Mysery as some would call it, is a game where you can walk and die alone, find some orcs and die in their company, or even advance in levels and die then: basically, a life simulator, just more fun.
On every run, you learn a bit more about the world and controls, so can survive a little longer on the next run. Probably at some point you will begin to read manuals, learn from the ADOM wiki, and so on – pretty much like with any other long game or activity. Then you will look back and regret that you have spent your time that way, or will be happy that you became closer to the end without being bored.
On the downside, it is proprietary. So, apparently there are long-standing bugs which don’t get fixed, and are documented in the wiki; its graphical version seems to support Debian (and derivatives) only; to run it in paranoid mode, one has to use something like sandbox -X -H . -T ./tmp xterm -e "sleep 1 && ./adom" (since it also requires graphical mode, and hence access to terminal). Newer versions, which include story mode and other nice features, are available only to those who paid for it, and all in all it seems to belong to the world of demo versions, ads, malware, and other unpleasant things: if you are playing this, you have already lost. It might be worthwhile to consider other roguelike games to play.