Bungie's Duality, modified with Bobs that shoot grenades or lava globs. The idea is to give people without access to a network the challenge of a net game. (SPN stands for Single Player Network.) Works okay, except that bobs will never shoot like real people... and not much care was taken with the physics model. (Although the shots are right, the sounds aren't... sort of strange when you hear pistol shots,and turn around to see lava globs coming at you.)

A small mazelike map, with an embedded physics model that keeps you on your toes. (It's designed to be played solo-the SPN stands for SIngle Player Network.) You get one magnum (and, if you kill the infrequent vacubob, a fusion pistol), and your job is to kill as many bobs as you can. (There is no end.) Good for target practice... the bodies really pile up. Enough recharge canisters appear that you can keep going as long as you want to.

A six-level, action-packed solo scenario. This was released (and announced on alt.games.marathon) last fall, but there wasn't any active archiving going on at the time.

A four level solo scenario. Mostly well-built, with nice architecture, and decent gameplay. Play would be better, I think, if it weren't quite so predictable.