Three independent levels connected by a start map.
Voidscape: Very small rocky island floating in space.
Brownie: Small medieval fortress with an atrium and tower areas.
For The Love Of Evil: Large Metal/runic map with majestic halls and various traps. (On hard difficulty, the map exceeds the max_edicts limit, so it requires a source port with increased limits).
Classic singleplayer campaign made by Gotshun that was never finished or released: Two episodes with 16 levels of various themes including a start map and a secret map. The second episode lacks a conclusion/boss fight due to the unfinished nature of the pack, but it is perfectly playable.
A medium sized cargo spacecraft with Zer and IKBase textures and somewhat unusual gameplay. There are three missions to be completed in which you'll face all kinds of problems, from technical difficulties to unruly 'cargo'.