Styx has been revisited several times. The original structure of the level has been kept, though retextured and beefed up a little, and forms the core of the new level. Around that I have added a lot of tunnels including some airducts and railway tracks blocked on both sides to provide a lot more connections and atmosphere. The expansions have been inspired by Kruel's missions, and the Descent 2 textured level contains a few of his (public domain) custom textures. The latest instance of Styx features Descent 3 textures, a lot of D2X-XL features like smoke, lightning, timed trigger effects, and allows 15 players in multiplayer games. Enjoy.
