Like others have said, Dark Souls and Demon Souls both used XP and currency as the same item. IIRC, Yahtzee didn't get too far into one of them because of how difficult it was and it felt too much like Stockholm syndrome to him. I think a more accurate depiction of the games would've been the way you, the player, develops skill in addition to the players character-going through a 2nd time on either of those games, things feel very different and go much smoother because you've learned a lot about how things work, beyond just basic mechanics for damage and such, and are genuinely better at the game in a non superficial or knowledge (the kind you look up on a wiki for an RPG, for example) way.
Also, not terribly relevant, but System Shock (the original) had rocket skates >.>
I know The Ship and The Ship 2 combined sims-like gameplay with shooter, but with the multiplayer most people wind up dieing before they need to fuel their sims needs (probably because of server setups)... I like a lot of Yahtzee's ideas, but there's the question of how well they're executed, too. Hopefully we can see some more unique and good games like he's suggesting.