Mass Effect: Revelation is related to the Mass Effect video games. I'm not sure about how close it is to the video games, because I haven't played them. Revelation stands completely on its own as an exciting story in a well-developed settingA man in Earth's space military is sent to find a woman who went missing when the space station she worked on was attacked. Different factions work together or against each other at different points in figuring out what happened and how they could profit from it.
I wasn't expecting a ton from this book because it's a video-game tie-in by a newish author, but it was more entertaining and engaging than I expected! I didn't feel like I was missing on plot elements by not having played the game or anything.
The setting is the strongest part of the book, I thought. It's a really neat concept with lots of alien races and complex cultures. There is some background tension, particularly between humans and aliens they've specifically pissed off.
I would recommend this book as a stand-alone science fiction adventure story. It's a quick read and very exciting, but without a ton of depth.