Ad/Free, roguelike dungeon crawler. Starts off limited, but by joining different factions(on can freely swap once you've initially joined each) you can unlock classes, races, backgrounds, and Contracts - equippable packages that allow you to influence your gear, skill, and rune rolls.

When a run is over, you are give a selection of parts from the corpse to attach to a specific race/class combination, granting persistent stat buffs for a character. Deeper dungeon levels yield better parts, natch.

While in a dungeon, besides leveling up, you get soulstones from defeating enemies which can be used to reroll any gear/skill/rune drop you get. You can also use your contracts at this point to spend those soulstones to directly acquire a thing you want at an appropriate level, letting you essentially lock in important gear and skills.

There are more subsystems than I have the attention span to detail here, the game is deep.

Honestly the main reason I'm even here typing this for Steam is because this game is ALSO free on Android, and easily supports a save transfer mechanic between devices, so I can play on my home PC or on the go. I've actually played about 30 additional hours on my phone that haven't been logged here.

Bottom line: If you like dungeon crawlers with untold depth and customization, give this free game a look.