Bungie's first big hit, Classic Marathon, is free on Steam with Marathon 2 and Marathon Infinity to follow

Bungie's first real shooter hit, Marathon, has been released on Steam for modern hardware as Classic Marathon, a fan-led port that has Bungie's blessing to release. Classic Marathon is completely free, letting you have the rare experience of playing a classic game not only easily but with zero time spent hunting down an old copy and fighting with compatibility.

Marathon is a sci-fi FPS where your character is in charge of fighting alien forces that have boarded a human colony ship in the distant Tau Ceti system. Your job is to defend the ship and the crow of the Marathon, but discord among the artificial intelligences that run the ship and factionalism among the alien attackers become the key points of the plot.

Having a plot at all was a pretty big new thing for first-person shooters back in 1994 when Bungie first released Marathon. Alongside System Shock that same year, Marathon pioneered the idea of giving the story through characters you can speak with and environmental objects to read. It also pioneered cooperative first-person shooter campaigns, which the port still has, and which were still quite rare even when Bungie later made one in Halo: Combat Evolved.

The re-release is powered by an open source engine called Aleph One, which fans have been using to maintain Marathon for about a decade now. That lets them have some real fidelity to the original, but also features you definitely didn't have in 1994.

"Experience authentic game play using the original data files, with optional widescreen HUD support, 3D filtering/perspective, positional audio, and 60+ fps interpolation, just in case the original is too authentic," the Aleph One devs say.

You can find Classic Marathon for free on Steam. There are also pages for Classic Marathon 2 and Classic Marathon Infinity, which are set to release in the future.

The debut of the classic game on Steam is pretty timely, because Bungie intends to reboot the series as an extraction shooter some time in the near future.

"A massive ghost ship hangs in low orbit over a lost colony on Tau Ceti IV," the Marathon website says, setting the stage for the game's narrative backdrop. 

"The 30,000 souls who call this place home have disappeared without a trace,"  runs the pitch for the reboot. "Strange signals hint at mysterious artifacts, long-dormant AI, and troves of untold riches. You are a Runner, venturing into the unknown in a fight for fame… and infamy. Who among you will write their names across the stars?" Playing the original, I'm sure you'll see some familiar ideas and names crop up.