A fun romp through a bunch of rooms... a couple of secret ammo dumps to find, and basically just a lot of carnage to keep you busy for a while. Update adds a couple of terms, courtesy of Hex!
A really nicely designed level. No fancy lighting effects, but you'll be too busy staying alive to really notice... Documentation says Ignore Zero Divides is necessary for 68K users, but the map worked fine on my Q800. Crashed for the developer on an fpu-less 040, though...
This is in the same vein as 20 Minutes of Hell, for you M1 solo players. No plot (well, there is background in the readme, but it's mostly just window-dressing) - the point is to kill and stay alive as long as possible. A good stress-burner.
Big, and geometrical. Lots of nooks and crannies... play it once before you get your friends together for a net game-it's in your interest to understand the switches before you begin.
4 maps. A couple of these are built like layer cakes (hence the name). The best one, Soggy Layer Cake, has a bizarre bug that causes it to crash ONLY Powermacs. (I've never seen this before.) It runs fine on 68K machines, though...
Michael Hanson's Physics Model editor for Marathon 2. Make flying bobs, or flame-shooting pfhor, or... whatever you feel like. Update fixes lots of bugs, adds a couple of features (customizable lists!).
A simple arena, with lots and lots and lots of shotguns, lots of blue pfhor, and one spanker. Great as a practice arena, too (there are never fewer than 4 blues alive at any point).
A pretty nice level with a mission. Get the repair chips... No terms, but a couple of very nice perks. Up to Bach's high-quality standard for solo maps... Cool beginning, nasty ending. (You'll see.)