Just two weeks after Daniel Blezek spilled the beans on his Bungie-authorized Marathon iPad port, the pre-Halo first-person shooter has been released today. On Bungie Day 2011! What a coincidence!

Oh yeah, and it's free.

For those who had their PC gamer blinkers on in the '90s, Marathon was a Mac-only first-person shooter trilogy, almost always compared to Doom. And though it didn't garner as much attention as Doom, it's still considered a seminal genre piece.

There's no sign of an iPhone version quite yet, but we'll keep you posted on any goss.