Most mods of a game are simple reskins done for comedic effect or out of love for a TV show. Some are done to tweak the rules and make a better game. And some basically turn it into a whole new game. Doom: The Mercenaries, would fall into that last category.
Essentially, it’s Doom with Resident Evil 4 characters… who have kept all their abilities. HUNK can break necks, Leon can put boot to face, Krauser still has that freaky blade-arm, and so on. See for yourself…
What’s interesting about this, from strictly a gamer perspective, is how carefully they’ve incorporated the mechanics of the two games. This is definitely Doom, but the game on screen is undeniably Resident Evil 4 as well. It looks like you can essentially pick up the game without a hitch.
It also sadly looks more playable than half the games in either franchise, these days, but really, that’s what fan mods are for. As long as we don’t have to try and fight cyberdemons as Ashley, we’ll be good. The video is from the 4.0 version, which is almost complete; if you’d like to see the last version, you can find it right here. You’ll need Doom and either Skulltag or Zandronum, the multiplayer ports of the game.