Bioshock 2: Minerva's Den combines the great gameplay of Bioshock 2 with the awesome storytelling of the first Bioshock
The game starts off with you walking around in a new part of Rapture, trying to find a Supercomputer known as The Thinker for Brigit Tenenbaum. However, the main antagonist, Reed Whal tries to kill you with mines. This is where the story starts. You are led by the nose by a man named Charles Porter to find The Thinker so that you can escape Rapture. Porter functions the same as Atlas, very amiable and a great leader. The story experiences plenty of twists and turns and also has a great ending. The new antagonist, Whal, is very different from Lamb, Ryan and Fontaine. He is a lot more paranoid and visibly crazy. in this he is similar to Gil Alexander from Bioshock 2. He isn't a great enemy, but he isn't a super weak one either.
You function the same as Subject Delta except you can now find new Plasmids, weapons and tonics. The weapons, plasmids and tonics are given to you much faster, simply because the DLC is shorter. While the DLC is shorter, the game paces itself very well so it feels much the same as playing the main game. There is plenty to explore, new enemies to fight and more diaries. Most of the diaries are from Charles Porter, and these gradually explain the creation of the Thinker, and in fact much of the story. Another added thing is this really fun game that you find called Spitfire. It's a really basic but fun computer game and can be a small entertainment for around 10 minutes.
Without wanting to reveal too many spoilers, it is hard to describe the story, but in my opinion it is nearly as good as Bioshock 1. The game play is much like Bioshock 2 with enough differences that you won't get bored easily. The audio diaries are great as always and the new enemies and antagonists provide enough value to keep you entertained. The only thing sad about this is that it is too short compared to how good it is. It is well worth the 800 MS points even if it has no replay value. What you are buying is the great story, and the awesome game play is an added feature.