Catacomb Abyss

Before Doom, there was Catacomb Abyss, where you throw fireballs down corridors at zombies who all apparently graduated from the same school of slow shuffling. It's a first-person shooter without the “shooter” part—you’re a mage, and you’ll spam fireballs like you’re overcompensating for a weak Wi-Fi signal. The graphics are chunky, the sound effects are crunchy, and the fun is surprisingly legit for such an early FPS. Bonus points for having walls that actually feel evil.