I've got a few suggestions, best if you are going commercial.
These are all very common mistakes, and some are directed towards you.
1. Remove the guns, and add TV's and stuff at your house. Why would you keep guns on tables 24-7?
2. Add a little more to the story, give this guy a reason to be calling you and holding your family ransome. Make your house look really big so you look rich or something.
3. Try doing custom models, modern terminals are alot bigger then that.
4. Make the part where you answer the phone actually real, if it isn't.
5. Add a couple of civilians to run around, along with some unarmed police officers so that they don't automatically shoot you, if there isn't.
6. Not particularly to you, but this is a very common mistake among FPSC games, but I don't think you will - Make sure you edit the textures so the arm is always the same on the same mission, if you use both model pack 5 & 6; I don't see why you would put on leather gloves just for a desert eagle.
7. Make the story a little original, talk to some people, take a couple college classes, if you can't already, and make a full story line. The world's most failing games are ones where it just loads a long line of levels. If it were me, and that was my thesis statement, I would have him run you around the city, and give you clues.
8. Don't let your player just start out with a ton of weapons, give him fists to start, and a AT9mm on the second level or something.
It looks good otherwise, but if you plan to go commercial, you might want to fix it up a little bit, and fix the lighting.
I highly recommend you stick with Model Pack 5 & 6, they are the good ones. (Or of course, if you like to do 3d models,
Death is only the end of the physical realm, eternity in the astral plains awaits you. But people are ugly there, and there are not very many multiplayer video games. So stick with earth for a while.
