It's a simple scenario, small with few special rules. I have posted it on BGG should you wish to check it out, It's been playtested once with my bro. If you tried it, please comment on it. Only the original game box is required, but using the expansion equivalents is ok.

NOTE: The scenario is designed for 1 marine player. Games with 2 or 3 marines should use Ultra-Violence and Nightmare modes from the expansion if possible.

Sounds nice, but I didn't find the link in your post yet

How long usually it takes for a file to be verified?

Ah, you posted it to the geek? The last one I submitted took about 3 days...

Alright then, well it'll be there sooner or later

4 player version would be nice.

As I said, it is possible to play with 2 or 3 marines. Just increase the difficulty

It's on BGG! The link is now up