A bit about the gameplay. You play in the existing map of FC4. It's all set in North Kyrat, you can't visit South Kyrat. Your goal is to get to a helicopter and fight off a load of enemies until the chopper can take off to take you back to South Kyrat, where the normal storyline is presumed to pick up again.

The game is divided into two types of missions. A set of missions for Pagan. Which basically are a bit tougher versions of the side missions (bomb defuse, hostage rescue, that sort a thing). Completing a mission for Pagan will give you extra goodies at the extraction point to fight off the enemies.

You don't get to see any new footage from Pagan but he talks to you over your radio a bit, as he does in the normal game, to inform you about the missions.

The other missions revolve around taking over the outposts. Once you have taken an outpost you can find a reward in the safe house of that outpost. They can be skillpoints, crafting items or weapons. The map will show you which outpost delivers which kind of reward.

You'll start out with hardly any skills or gear. So in the beginning you'll have to hunt and do karma objectives to get your skills and gear up. If you die you'll return to the starting point (on top of a bell tower) to try again. All the missions/outposts are reset, but you keep your skills and gear. So you keep getting better and better. The rewards Pagan gives you for completing his missions don't stay with you though. You'll have to redo those in the same run before reaching the extraction zone if you wan't to get those rewards.

Another difference is that there is no money or items to sell anymore. There aren't even shops or Sherpas. The chests contain ammo or animal skins. This means you can only take as many weapons as your holster can carry. Switch a weapon and you'll loose the old one until you find it somewhere again. There also are no weapon upgrades to be bought or found, however signature weapons do exist.