Killzone Review - GameSpot

It's a functional shooter, but with a couple of extra coats of paint, Killzone could have been a whole lot better.

Killzone 3 - Wikipedia

Killzone 2 Video Review by GameSpot

Killzone: Shadow Fall Reviews - OpenCritic

Killzone 2 - Wikipedia

Killzone: Liberation Review - GameSpot

Critical Consensus: Killzone 3

Killzone 2 reviews and the rush to be first – Destructoid

Killzone: Mercenary Review (PS Vita)

Killzone 3 (2011) - MobyGames