When your entire game builds to a final, bombastic mission as in Mass Effect 2, it's hard for any downloadable content set after that point to not feel like an afterthought, and that's certainly true of the "Overlord" DLC from a structural standpoint. But when even your afterthoughts pack more fun and emotional resonance into a couple of hours than many games manage in their entirety, who's complaining?
When Commander Shepard and his crew were first called in to investigate a powerful virtual intelligence that had gone rogue, I was worried that "Overlord" would suffer from the same tacked-on feeling as did its predecessor, "Kasumi's Stolen Memory." Maybe you didn't hear, but I recently saved the galaxy -- why am I suddenly thrust into the role of interstellar IT guy?
I needn't have worried. While "Overlord" has little bearing on the whole of ME2, it's far more self-contained than "Kasumi," with its own arc and own emotional wallop. It's a fitting conclusion for a game head-and-shoulders-and-most-of-torso above others in its class in terms of storytelling.
Sadly, this is the last Mass Effect 2 DLC, but [Update: Sorry gang, totally misread that line. There may be likely be more DLC, just no new characters.] BioWare has taken the opportunity to throw a little bit of everything in and see what sticks. Want full-bore action? You got it. Want to solve tile-shifting floor puzzles? No problem. Want to do some light vehicle-based platforming? Well, you probably didn't know you wanted to do that, but it's here nonetheless. You won't be bored, let's put it that way.
Overlord doesn't jam new characters into your game or add a load of new weapons, but it more than makes up for that with a haunting little story of family, betrayal and sacrifice. Note to other game developers: If you're able to pack that into two hours, you'll always have my seven bucks.