Recs.
Updated
The Dark Mod started life as a Thief-inspired total remake of Doom 3, but now it is a standalone release, a complete game that anyone can play for free.
"I would absolutely recommend The Dark Mod. In my opinion, it’s one of the greatest free games out there. It was born out of love for the classic Thief games and is an excellent reflection of those titles. In fact, if you’ve never played the Thief games before I would recommend checking this out first just to get a taste of what they’re like. The Dark Mod is a Thief game without actually being a Thief game. Definitely check it out" according to Gaming Pastime review.
SpecsUpdate
Pros
Pro Free to all
The game is a community remake of the game Thief, not in terms of story, characters, or levels, but in terms of mechanics. Originally it was created as a mod for Doom 3, but has since been remade with original assets in order to have no liability, though it still uses the same mission. This means the game is free and will stay free. Players can download dozens of additional missions at no additional charge.
Cons
Con Old-ish graphics
Although efforts are being done to keep it nice, The Dark Mod runs on an engine from 2004 and definitely looks dated compared to modern games.