Supposedly, a map located inside a borg ship, from Star Trek. It is indeed a cube shaped map, with several levels, custom textures and reskinned army grunts and enforcers that shout soundbytes from the show. In short, it’s terrible.
Everything looks the same, some doors get in your way, when opening. The key that opens the exit portal is behind a shootable button that looks exactly like any other wall and the textures are terrible.
Awful.
Link to Nightmare 100% walkthrough: https://youtu.be/ySPnAB9q0Jg