The only reliable way to play Killzone 2 on a PC is via – the open-source PlayStation 3 emulator. Over the last two years, RPCS3 has made staggering progress. Killzone 2, once considered "unplayable" due to massive graphical glitches (the infamous "black screen" or "invisible enemies"), is now fully playable on high-end hardware.
: If you want to jump back into the "Warzone" multiplayer, you can use
A Masterpiece of a Game, Trapped in a Non-Existent Port