Assassin's Creed IV features what may be considered the oddest choice for an assassin yet, Edward Kenway, a pirate and friend to Blackbeard. This brings up all sorts of questions about the true history of pirates in the AC world but we'll have to get to that another time. In the floor demo for E3 they showed two main aspects of the game, combat and stealth. The combat portion of the game started with Kenway tailing a man to to a group that wants this pirate village knocked out. He kills the enemy scouts that might find him until he reaches the camp. At the camp from an overhead vantage, he jumps down and kills two people with a hidden blade and shoots the other four. This all looked like classic AC. Even with all the spies dead it was not enough and a British (I'm assuming, so don't hold me to it!) fleet attacks the town setting it a blaze. Kenway then free runs through the burning city to get to his ship and counter attack. Despite the fleet getting the jump on Kenway, he manages to immobilize a ship, board it and take out the soldiers. This part of the demo ended with Kenway and Blackbeard prepared to take on the overwhelming odds surrounding them.
The second demo had more to do with the world exploration aspects of the game. After accepting a contract on a set of captain brothers that, well I don't know what they did, but we accepted the contract non the less. The first bother was easy enough to take out as he was hanging out in the local bar. Kenway walked up to the brother, nonchalantly grabbed the target's head and smashed it into the bar. This scared the other brother and as a result booked it to his ship. Kenway jumped on to his boat and followed the brother, disabled and boarded the ship, and finally killed the captain (your target) and most the crew. The ship was then given a pirate captain and sent to join Kenway's fleet. The demo continued with a treasure hunt that involved using stealth to go around a number of Spanish soldiers and freeing other pirates.
All in all the game looked very much like a traditional Assassin's Creed title. It would appear that not all of the architecture will be as epic as AC II, but with the local of the Caribbean we could be seeing Aztec and Myan ruins to climb. Look for it to come out for all systems late October.