Killzone: Shadow Fall: Intercept
Originally a DLC for Shadow Fall but nowadays also available as a stand-alone game through PSN, Intercept is a co-operative mode where four players have both to hold their ground and keep control of certain strategic points against progressively more challenging waves of AI controlled Helghast enemies.
The players can retrieve certain items scattered across the map to purchase upgrades or trigger certain events, such as activating automated turrets around the map.
Working on this DLC was a blast, as we pushed the network code to the breaking point: the AI had never supported networking before and we suddenly found ourselves with 4 players, dozens of AI entities and at any given time the host could drop off and the game session was expected to migrate.
Tracking down some of the bugs cause by session migration was truly challenging (e.g. needs three players in-game, host drops, all AI entities disappear… 5% of the time, have fun) and some of the systems were quite entertaining to add. The artillery was a personal favourite, as it remained virtually unchanged since I implemented the prototype until the game was released.