Well, if u loved DOOM 3 u will probably enjoy this one
Graphic : Quake 4 works on Doom 3 engine (or id Tech 4, whatever u like to call it). That means that graphic is great. Good character and enemy models, rly precisely done. Level design is very well done ( I like The Strogg Medical Facilities most). Well that's about it,not much to tell, it's same like Doom 3
Sound : Nice work. Good Strogg voices (but,I don't want to have that voice), pretty good weapon, and explosion sound.Nice surrounding sound, and friendly radio is something that I loved to hear.In battle, when hear Strogg calling, and friendly chatting, that will make the u feel like in real combat.
Now, it still isn't Doom 3 but u should try it