Lots of experimentation on this one. A multiplayer map and a single player one which offers about an hour and a half of gameplay with a main storyline, loads of scary situations, a big big final boss and even some comedy.
The main bulk of my level designer work is in here. Three playable multiplayer maps with several versions and a lot of scenarios that were either just experiments, unreleased work, or parts of the movie that was never filmed; a lot of work went into that and with it a great learning experience regardless.
I used Quake III to learn the basics of level design, it's a simple gameplay and you get complete freedom of choice when it comes to themes. Two released maps and a gorgeous looking experimental one that never performed fast enough to be released.
Only one map for Unreal Tournament III. More than a building process, I wanted to get to know an engine that works very different than the Quake based ones so, using pre-made shipped models, I built a small map and learned how to make it look and work good.