Killzone 1 is the very definition of vanilla. The environments really look good but they're unnecessarily big and empty, the story is color-by-numbers, and the enemies are super-generic (and I play a lot of FPSes, so I'm virtually immune to generic enemies). It was an undeniably average game that was hyped up to unjustified proportions. IGN gave it a 7.0 and I think that's dead on. All the pieces are there, they're all decent enough, but there's nothing spectacular.