Victory Conditions.

In Killzone, there are essentially three types of playing- Story mode, Battle grounds; offline and online.

For the story mode, the victory conditions are pretty clear, as they are in the others... The player must make their way through each of the levels, avoiding death and accomplishing the mission objectives in the level. When you beat a level, you move on to the next. For three of the levels, beating it unlocks a character for you to play. Once unlocked, you can choose to play any of the characters at the start of a level. The story levels are pretty linear and each one ends the same way no matter what way you take/ the tactics you use. Get through the levels, moving 'up' a level to the next until you run out of levels to beat.

In the Battlegrounds, there are a few ways to win, usually involving points or kill count. The win conditions are related to setting the player chooses, namely amount of kills required to win and time limit. If a player gets the required amount of kills needed to win before the other one, that player wins. If neither player scores enough kills or points to win before the timer runs out, the player with the most amount of kills/points wins.

That's essentially it, KZ is about as straightforward as they come in terms of games. Its victory conditions are the same as any other FPS out there.