Frayed Knights: The Skull of S'makh-Daon
This is a party-based first-person RPG, with free movement in a 3D world and turn-based combat. I guess the closest thing would be Wizardry 8 or Wizards & Warriors. It's a little clunky (it's basically the work of a single developer), but it plays fine once you put a little time into it.
One of the greatest things about this game is the world design. It's definitely not an open world game, but it's cool to explore a truly 3D space in an otherwise traditional RPG. The dungeons are really good, with plenty of puzzles, gimmicks, and verticality.
There are also some very cool mechanics in this game. You can rest anywhere, but your chance of having a random encounter while resting increases if you try to rest in an area where you're out in the open. It's better to find some corner of a room to rest.
You also have what's called a "drama star" system, where you build up "drama points" the longer you play; you do retain these points if you save and quit and then continue from the main menu later, but lose them all if you reload a save. You can cash in these points to do all sorts of things, including reviving incapacitated characters for free. It's a cool system to reward you when you roll with the punches, but doesn't really penalize you for not engaging with it.
Having said all that, there are a couple of things that may be dealbreakers for some.
First is the humor. It's a "parody" RPG, with characters breaking the fourth wall constantly. The title maybe tells you all you need to know about the humor in this game (personally, it's not my cup of tea).
Second is the fixed party. You don't create any characters, but instead must play as four set characters. They all have their own roles and personalities, and the story of the game is told through them interacting with each other. You can choose how they develop as they level up, but you probably don't want to go too much outside of their fixed roles (fighter, thief, cleric, mage).
Grim Dawn
A Diablo II clone, but a good one. I got seriously addicted to this over the past few days. It has a look/atmosphere somewhat similar to the movie, Brotherhood of the Wolf, and some fun mechanics like being able to dual-class, freely add components/augments to equipment at any time, and unlock abilities and bonuses in any of 82 "constellations." This gives you several things to consider as you build your character, which is fun in a game like this.
It's a great game to just play for an hour here or there as I have time. It's not anything complicated (at least not on Normal difficulty), so I can just jump in, enjoy slaughtering a billion skeletons or whatever, and get some awesome loot. Fun!