If I were to make a FPS it would be this. The setting and the premise are so cool. The huge, wonderfully bleak, wasted industrial landscapes are awesome. Running around doing missions, scaveging loot from fallen enemies, talking to other characters you meet and trading with them and doing the occasionl job for them, killing all kinds of mutants and stuff, and lots of cool Soviet/Russian weapons.
There's also the realism aspect; you have an encumberance limit, you have slots in your inventory for a main weapon and a backup weapon and you can only have one of each equiped at one time, and weapons wear out with use and begin to jam as they degrade. There's even a cool little paper doll image of you that changes when you equip different armour so you can see what you look like. It's right up my alley.
The only problems are the bugs (but you get that these days don't you) the respawn, and the graphics. Respawn is never a good thing in games and usually ruins them, and in one particular area it ruined it a bit for me. You fight through a hoard of bandits at a road block to get through to the next area, and when you come back they've all respawned and you have to kill them all again. What's fun about that? The graphics are nice but seem pretty average to me. Some older games like Far Cry and Doom 3 look better and run perfectly on my machine yet this one runs poorly except on modest detail and lighting settings. Can someone explain that to me? There's terrific atmosphere in the underground areas though.
Other than those few niggles I'm enjoying it more than any game I've played in a long time.