The creator of the ENB series of mods, which serve as foundation for some of those quite impressive graphical enhancements for GTA IV and Skyrim, among other games, is now going after a not-too-well-known hack and slash game from 2001. The results... well, you should probably take a look.
The game, Blade of Darkness, is a 2001 third-person game with a slightly Dark Souls-ish level of difficulty, and slightly fighting game-ish weapon combos. It originally looked something like this:
And via copious amounts of post-processing, it becomes what you see in the video above. It's quite convincing, really! But it's really unfortunate that behind all the depth of field there's still only low-resolution textures and slightly janky early-aughts animation quality.
Do note that with or without graphics mods, Blade of Darkness is a very fun little hack and slash game. If you fancy a challenge, you can grab it from GOG, and to take a look at the mod, you can visit its ModDB page.
Unmodded game pic courtesy of GOG.