5 more... a mix. Launching Pad is great, but really slow on slower macs... and there's a map here that reminds me how much that Alien textureset hurts my eyes.
5 maps, again... all great maps (some of the best of the M1s), but again, the textures will hurt your eyes. (They're still fun, though...we hit 12 dpm again on a 2 player game on Cylinder...)
3 levels. These didn't thrill me as some have... and Circle Jerk has a bit of smearing if you're looking at the platform next to you as it moves (somewhat unavoidable, given the Marathon engine). Still fun, though...
5 levels. A couple of them are great (Mount Pfhorabachi, Out of the Closet) and all are very playable. Up on a Pedestal is a little rough if you miss a weapon at the start, but I guess if you do, you won't live long, so it's not really a problem...