OK you said :
Quote: "This is my first game so I'd like as much feedback as possible"
so here goes.
Media:
Good work with the custom menu, but you shouldn't be worring about that. Start looking at the media you're using in your level. If you are using stock stuff, try re-texturing it to look different, otherwise your game is no different from any other.
Level design
Your levels have not made people go WOW because they are a bit dull, try making rooms more than one segment high, and try adding more entities, crates around those artillery guns, old magazines and paper on the barracks floor. Giving your rooms height helps to inspire a sense of awe in the player, if height is unsuitable, then you're gonna have to convince the player they're in the location you're telling them. YOu have to break up those long wall and floor sections with pipes, conduits, boxes, lights, paper, filing cabinets, everything. It needs to look like the place, without you having to say "it's a hangar".
Try experimenting with the 1,2,3,4,5and6 keys for placing entities. Use them with shift too, allowing you to place objects on interesting (and more real) angles.
Lighting.
right click a light and open the colour tab. from the bottom of the tab select "other" then select "custom" from the new tabs at the top of the window. THIS IS WHERE YOU CHOOSE COLOURS FROM!
Using the standard FPSC light's makes your level look like a gunfight in a disco, they're too luminous and harsh.
Good luck dude. I'm not trying to be a horrible Criticism Troll, I've just been here a while and I'm trying to help you be different from every other next FPSC user!"
Peace and merry crimbo
Butters