Gun

Watch the video! Make sure not to be in the cannon's way in the end of the level - instant kill!

Wait, we just spent all that time breaking out and we're going back for some more? These Indians sure do hold a grudge, can't blame them I guess. Just a warning, this mission involves a lot of killing and is fairly long. From the start head along the river, kill the enemies that attack and then get in the canoe. Head towards the cave that you escaped through last level, on the way there you will find some enemies and a few barrels of TNT. Persevere onwards through the cave and up the ladder. This little area is littered with about 10 or so enemies, kill them all and then head through the building where the last enemies you faced were.

On the other side, you'll be greeted by a nice gatling gun. Shoot the enemy manning the gatling gun and take possession of the gun and use it to kill the enemies that attack before entering the warehouse like building. Clear the building of adversaries and take control of the cannon, as with previous experiences you have infinite ammo so launch those cannonballs! With this cannon you must destroy the four bunkers (which don't actually look that much like bunkers to be honest, although they're easy to see and all next to each other making your work easy. Onto the next cannon, kill its owner and then use it to put some holes in the boats.

After you've done so, move onto the next cannon, on the way there's some enemies but you get some Indians to help you out. With your newly found firepower, aim towards the ammo dump and shoot a couple of times (one didn't do the trick for me) and then enter the hole. Keep on going, killing the enemies as you go and you'll reach a fourth cannon but you won't be taking control of this one, instead you must destroy it with some of that explosive red stuff. Dispatch the enemies on the other side and then throw some dynamite over at the cannon - this can be tricky to judge so just go full power and you should get there - if you happen to run out of dynamite then head back down into the room and snag some more. Job done!

Utilizing the cheat as mentioned in the Achievement Guide for Insane Difficulty Complete, this achievement can be unlocked by destroying the cannon. Just follow the steps below:

1. Start a new game.
2. Activate the cheat using the instructions mentioned in the Achievement Guide for Insane Difficulty Complete.
3. Pause the game and select the 'Gun' option, followed by the 'Missions' option, followed by the 'Main' option, then select the 'Attack The Fort' level.
4. Once the mission has loaded, go back into the pause menu, then select 'Options', then the 'Gun' option, followed by the 'Checkpoints' option and then load the last checkpoint of this mission.
5. The last checkpoint loads at the point where a cannon has to be destroyed. Simply, select the dynamite, find some cover and then throw some dynamite at the cannon using a 'full powered' throw. If you are having trouble just keep an eye on the bar that appears in the bottom left hand corner of the screen to see how much power is being produced for your current throw.
6. If you run out of dynamite, just go back down the stairs and there are two boxes filled with extra dynamite sticks.
7. Once the cannon is destroyed. Achievement unlocked.