Hey, glad someone's still interested.
Funny you should say that because I was just about to release a MP version of it. I wasn't going to but I have had some requests. I have to say I still have the problem with the CSG Subtract showing up in MP but not SP. However, this doesn't detract from the gameplay.
If I get enough of a response and people want me to I may go back and relelase a second version fixing the CSG Subtract problem and adding a falling catwalk. Unfortunately, the only way I see to fix the problem is to redo it, and I just don't have time for that right now. Maybe once I relelase the first version someone will know how to fix it.
So fear not Skellington, at this very moment I'm trying to get the lighting down as best as I can, then I need to add some bot support which shouldn't take long at all. It'll be out any day now. Thanks for asking.