If it ain’t broke, don’t fix it. That’s what 2k Interactive (standing in for Irrational) must have been thinking when making this follow up to one of 2007′s most beloved new IPs. Bioshock 2 is more of the same, but when the original was as good as it was, fans won’t mind.

Set 10 years after the events of the original Bioshock (and assuming you got the good ending), you make a return to the doomed underwater city of Rapture. This time, you don’t take the role of Jack or some other offspring of Andrew Ryan, you are a Big Daddy. Not just any Big Daddy, you are Delta, the prototype. Now what brings you back to Rapture? Well, since Ryan’s death, Sophia Lamb has taken over as the new head honcho of Rapture. While Ryan had an Ayn Rand-influenced “everything for oneself” mindstate, Sophia Lamb believes in family and community, pretty much to a fault. Her followers sing praises of ‘the family’ with a cult-like furor. The terrifying Big Sisters roam Rapture’s hallways with huge needles that can suck Adam directly into their blood stream.

If you played the previous Bioshock, you know what to expect: upgradable weapons, plasmids, audio logs that give details about the story, and bizarrely twisted enemies. While you are supposedly a big daddy, you don’t have the power of one until later in the game. Of course because you are a big daddy, you have the option of using the little sisters to harvest Adam (the game’s form of currency for plasmids) from dead bodies instead of simply freeing or draining them. You also get to wield the drill, but you need gas for it.

Most of this game’s caveat’s stem from the fact that you’ve seen most of this before. This isn’t necessarily a bad thing, as the original Bioshock was a classic. However, you get the feeling of missed opportunities. For instance, the Big Sisters were originally planned as a single character that stalked you around Rapture like the Nemesis creature did in Resident Evil 3. Instead, they are just glorified boss battles. Yeah, there are plot twists, but nothing as shocking as “would you kindly”. The multiplayer is a novel concept, as it features upgradable plasmids and takes place before the fall of rapture, but still, it’s not gonna make you toss out your copies of Halo and Call of Duty.

Now don’t take these criticisms as if Bioshock 2 is mediocre. Just the opposite, it’s every bit as memorable as its predecessor, even if it does suffer from the law of diminishing returns. Yes, you’ve seen it before, but you’ll still have fun. Beside, it will tide you over until Irrational takes the series in an all new direction with next year’s Bioshock Infinite.