4 maps, the gameplay is average or just above for all of them. The level construction feels a bit rushed with numerous small errors in all maps. For instance, you can get up to the *sky* on Pennance and camp away to your hearts content (rocket jump up near the powersheild location). About half of the models are non-solid. I don't think releasing these 4 maps as a Tier Mod has been of any benefit. The author has put in a lot of work, but the Tier would have been a lot more succesful with more time spent finishing the maps off properly.
Probably would have been better released as a plain old pk3. Also the pk3 is not a compressed zip (unzips to 20meg).