Back, back, back when we are all a lot clearer on what 'indie game' really meant, there was a series of roleplaying games from Jeff Vogel's teeny-tiny studio Spiderweb Software. They were 2D, they were resolutely singleplayer, they offered massive freedom of movement and character development and... well, I keep using the past tense, but Spiderweb have kept on fighting their good fight since 1995. In fact, this week they're capping up a spit'n'polished'n'ground-up redone remake of their early-noughties Avernum series. Which was itself a spit'n'polished'n'ground-up redone remake of their mid-90s Exile series.
Which might all sound horribly complicated, but they're billing today's quasi-new Avernum 3: Ruined World as a clean entry-point for anyone who's never been down this particular rabbit hole before.
I suspect, for the enirely uninitiated, Spiderweb RPGs might seem a little unapproachable, a mass of stats and skills and tiny sprites. Not a bit of it - my first-ever Vogel was 2011's Avernum: Escape from the Pit, the second remake of 1995's original Exile game, and I had no problems whatsoever getting into it.
These things' scope may be wide and the presentation on the old-fashioned side, but they really are designed to provide a good time, not a frosty, purist one, and as such are surprisingly rewarding of experimentation and random wandering.
I can't speak first-hand to Avernum 3 itself, but heck, there's a lot of pedigree behind it, and if you're jonesing for a meaty solo RPG that isn't saddled with thoroughly modern microtransactions or anything like that, you'll surely feel warm and comforted by it. It's out now, direct from the devs or from Steam, Humble and GOG.
If $18/£13.49 is too much of a blind gamble for you, extra-good news is that there's also a demo whose only cost is a 256MB download.