Killzone
The original "Killzone" is a first-person shooter game that debuted in 2004 for the Playstation 2. In first-person shooter games, players control a main character from the first-person perspective while gameplay centers around collecting weapons used to progress through the game. Playing "Killzone" requires that players have a Playstation 2, along with the appropriate connection cables, a PS2 controller and any brand television. Note that you can also play Playstation 2 games such as "Killzone" on the Playstation 3 console; doing so requires that you have the appropriate Playstation 3 connection cables and PS3 controller.
Killzone: Liberation
"Killzone: Liberation," a direct squeal to the original "Killzone" game on the Playstation 2, was released in 2006 for the Playstation Portable handheld gaming system. Unlike the other games in the series, players control the main character in "Killzone: Liberation" from a third-person perspective. This entry in the series requires that you have a Playstation Portable (PSP) to play the game.
Killzone 2
"Killzone 2," released in 2009, was the first of the series made for the Playstation 3 gaming console. "Killzone 2" follows the same first-person shooter style of the original game, but features enhanced graphics, downloadable content (DLC) and online play. "Killzone 2" requires that you have a Playstation 3 game console, along with the appropriate connection cables, a PS3 controller and any brand television. To access DLC, you must plug your Playstation 3 into a high-speed Internet connection.
Killzone 3
"Killzone 3" is the fourth installment of the series, released in 2011 for the Playstation 3. Gameplay and graphics resemble those of "Killzone 2" as the game continues to advance the overall plot of the series. In addition, "Killzone 3" offers offline split-screen campaign mode, allowing two players to play through the story progression of the game simultaneously. "Killzone 3" has the same system requirements as "Killzone 2." This latest entry in the series also requires a second controller to play the offline split-screen campaign mode.