Quake 2 uses sprites! The BFG's shot is made out of doom's BFG's shot sprite and they added an explotion sprite to the .pak that was never used. For some shots they used particels made out of sprites like the bluster's shot's trile, BFG had little particles around him and the rail gun's shot. : Most of the stuff are models! Like the hiperbluster and the bluster's shots, explotions(that looks alot better then Hl1's more real and 3D),monsters(of course),grandes and missiles(of course)...well there are other stuff that I don't remember.