Had a good look through it and here is my review.
Firstly, regardless of the fact that I wrote the music, if I hadn't i'd still have said this
I'm not sure if there really should be music in the menu screens. There is a yucky transition between the two tracks when you go into the loading screen and I personally think it detracts from the experience. Games like HL2 multiplayer etc didn't have music, yet they make a very atmospheric menu screen. Mabye a more innovative menu screen is required with custon buttons etc, to immediately grab the players attention and to make them think "Hmm, someone's certainly put alot of work in this."
The level design itself is nice and simple. It has plenty of guns and cover. Sadly I can't get the complete package as my monitor stretches everything horribly (This happens on all FPSC games) but that doesn't matter. I liked the contrasting styles of the top floors and basement but I feel that perhaps the transition into the basement should have been a little more gradual. You could have had one little extra room, like perhaps a security checkpoint: A small room with a window into a little control area where a guard would generally be stationed. I dunno, something like that.
Entities were fine, I liked the placement but I do agree with the others here. The area should perhaps have some battle scars.
I also think the lighting should be revisited. It was all a little too light for me. This level could be very tense and atmospheric if there was less and darker lighting. An example would be the dead soldier. The area under the platform could be very dark, with just the shaft of torchlight on the dead body. I also think the basement area could be changed a little in the sense of lighting. You made that awesome tram scene in your izolis beta. Perhaps a dark lighting scheme with hints of bright neon colours could work?
Lastly, weapons were nice and varied. Liked the little sci-fi themed ones too. It'll be much better when you have the hands. The same crosshair for each weapon would be nice though.
A different hud would be welcome here. I assume you will use the HUD you make for Izolis single player whenever you make it?
Notice that most of my comments are just little details that can be added later. I've just tried to spot as much as I possibly can and it's up to you whether you agree or not.
I'll give you a game soon!
