The Marathon scenerio that you thought was called

is actually called

...and you can download it here, or here, or (slowest) here.

System Requirements:

Mac OS 9 (Not Mac OS X)
90 Megabytes of hard drive space
40 Megabytes of RAM
3D Hardware Acceleration

Carlos on the Run was never finished. It has been a year since any work has been done on it. This is due to the fact that the "Bridges and Balconies" feature from the open source Aleph One engine was never fully developed. The only version of Aleph One that supports the 3D level design features found in Carlos on the Run was released in May of 2001. I couldn't motivate myself to continue developing content for a dead engine that only runs on Mac OS 9. (That sort of explains why I decided to make my own engine, which may be of interest to those with more powerful computers running Mac OS X.)

View the old Muerte Machine Web site here.