From a technical perspective, the shooter genre is one of the hardest to combine with a massively multiplayer format. Having 16 players battling online is one thing, but thousands of people shooting at each other on the same server is a whole different story. PlanetSide 2 has managed to not only accomplish this difficult feat, but also ensured that the gameplay is suited to the massively multiplayer format. There's nothing quite like being part of a platoon of 200 people, flying over an enemy base before dropping down all at once for a mass assault. Logging on to PlanetSide 2 really feels like you've entered a war zone, making for an often overwhelming, but rewarding experience that just about necessitates playing with a group of people over TeamSpeak.
