This Marathon mod 15 years in the making is practically an entirely new game

Apotheosis X hero art with marine blasting a floating alien in a dark, yellow-lit hallway

(Image credit: Bungie, user hypersleep on Mod DB)

It feels like every other day there's some cool new Doom WAD that spits in the face of God and turns id's classic shooter into FEAR or Super Mario 64 or something, but how about some love for Marathon, Bungie's Mac-exclusive Doom clone and clear spiritual predecessor to Halo? On October 1, modder hypersleep released Apotheosis X, an ambitious total conversion of Marathon Infinity well worth the attention of retro FPS enthusiasts.

Its aesthetic appeal is immediately apparent: Apotheosis X is much more colorful than the original Marathon games, with redesigned weapon and enemy sprites, as well as high resolution textures and a custom soundtrack. The first few missions are set on a human cruiser, the amusingly named UESC Gingerbread Man, and they remind me most of the starting level of Halo 2. It looks like Apotheosis X's 23 levels eventually take players down to the surface of an alien world and its requisite eerie glowing ruins.

Apotheosis X impressed me mechanically as well, with even basic weapons behaving differently than their vanilla Marathon counterparts. The pistol, for example, is now a projectile-based plasma gun instead of the original hitscan magnum. The missions I played had that boomer shooter sense of untying a level design knot that I crave, but I started to get the sense hypersleep might be really cooking with gas in the second map.

There are way more foes than you have ammunition to deal with here, but there are also switches to activate beefy friendly drone fliers throughout the level. I got into this rhythm of skirting past packs of enemies to smack the big red button and summon my pals, almost like calling my older brother to deal with some bullies. I'm curious to see if Apotheosis X builds on this mechanic, or, better yet, packs new and interesting quirks into each level as you go on, almost like a Nintendo platformer.

Apotheosis X was a long time coming. In its readme file, hypersleep describes releasing an unfinished version of it back in 2007 when they were a teenager, and only getting around to try and finish it in 2020. "As usual," the modder quips, "ambition eclipsed good sense and over the next two years nearly everything in the game has been remade from scratch."

That hard work and long time to percolate has paid off by my reckoning, and Apotheosis X is a commercial-quality retro shooter campaign you can play right now, for free. Installation is a breeze, you just need to download the Aleph One open source version of Marathon Infinity and copy the play executable into the Apotheosis X install file available on Mod DB.

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dark purple alien ruins with cyan highlights — (Image credit: Bungie, user hypersleep on Mod DB)

Ted has been thinking about PC games and bothering anyone who would listen with his thoughts on them ever since he booted up his sister's copy of Neverwinter Nights on the family computer. He is obsessed with all things CRPG and CRPG-adjacent, but has also covered esports, modding, and rare game collecting. When he's not playing or writing about games, you can find Ted lifting weights on his back porch.