Korrupted is a really nice looking D1 level great for 1 on 1 and fun with up to 4 players (any more and it will be a totall killfest).
This has the same rooms as the original Kortege, but I've slightly changed a couple of them, and created new rooms making the level bigger.
A fun hunting type of level with nice scenery and a good framerate. It also has a Metallica midi and an exit sequence.