Blood: Post Mortem

A weird fusion of old and new: unreleased alpha levels crawling with brand-new enemies. Has some of the most bullshit godawful levels in the game and also some of the greatest, some really strong non-linear complexes you can approach how you please. The devs assume you've already beaten the main game so they put you through the wringer in the early levels, starving you of ammo while letting powerful new enemies shred your health, but things start to even out later on, and after the truly trash aqueducts level (worst in the game) you get a series of great Cabal temples. They end with a lukewarm but tediously murderous boss, but then that's business as usual for an old-school shooter.