Dark Matter, I guess...
Sadly true, but I don't wish to encourage folks to seek that one out. Maybe if it gets re-released as a proper game.
Hm, Flashback? That can take many hours if you are playing it the first time. I mean, of course there are speedruns for some levels, but there is also a 15 minute speedrun for Oblivion. :-p At least the second level can’t be sped up very much (my best is around one hour, so maybe 30 minutes are possible)
In my opinion, playing it the first time, wandering around, enjoying the atmosphere and story, this game lasts > 10 hours. (But of course, it depends on your skills.)
That's a valid viewpoint, and was probably my experience with the game as well (too many years have intervened for me to be sure). I've taken it off the list, thanks.