There is an interview on Gamers Hell with Project Leader Slava Klimov about Firestarter, the upcoming First Person Shooter from GSC Game World based on the FireStarter Engine:
Where does most of the action take place? Who are your enemies?
There are 16 levels in Firestarter. Any single player level can be selected for gaming in multiplayer. All single player levels are split into 4 episodes (such as Industrial, Empire etc) each containing 4 levels. Most of the levels are indoor or pseudo-outdoor ones. Talking about the level design, it is fully futuristic. We focus our efforts on four main topics - industrial, imperial, space and excavations, but these rather serve as directional points for the general design, than tie us to certain style. Talking about the level design, it should be noted that every level will consist of zones with only one of them reachable once you start the level. But others will unblock as you go (or creep, or strafe, or hide ;-) ) through the level. This is a good tool on one hand to keep the where-the-hell-am-I factor low, by temporarily confining the travel space for the player.