In addition to what defender and Guitarman have said I'll also note a few more. There are treasures of a slavers kingdom and wumpus 2000, both if titles like kerkerkruip but with proper rpg mechanics.
There are several dos games which possibly can be run in dosbox I don't know, it's a shame since fallthru particularly rocks.
If we're talking gamebooks there is also the fighting fantasy project and project aon, and indeed the chronicles of arborell, the ff project gamebooks particularly have statistical combat, as I believe do the delight games ones on Ios though I'm not sure.
speaking of Ios, there is a dark room, the ensign, king of dragon pass, nano empire (though that one is a little more of a strategy game I think), I don't know how the adventure to fate games are doing at the moment but they're worth a play if they will still work, hopefully touchmint will update them to work with ios 10 and 11.
there are possibly more I'm missing, but check the db.
Also don't forget that there are now a few browser games at least and oddly enough of a couple of muds that are actually more single player than multiplayer.
I'm thinking particularly here of puppet nightmares which has actual story, heavy combat and very optional pvp, and in muds of Frandom which is virtually a giant text rpg or if game in it's own right.
Hth.
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.)