As a science fiction fan, who enjoys watching space opera like Star Trek, Star Wars, Babylon 5, Farscape and Firefly, and who also enjoys reading literary space opera like Revelation Space, The Culture and the Hyperion Cantos, playing Mass Effect was like a dream come true. It was a space opera, as deep as a novel, but with the artistic beauty of Star Wars.
The world's best RPG maker, (or at least, western type RPG maker), BioWare, are renowned for creating deep and intelligent games, with great plot, characterisation and artistic design. Their Star Wars RPG, Knights of the Old Republic, was more popular with Star Wars fans, than the prequel films. When they set their sights on creating their own space opera franchise to rival Star Trek and Star Wars, they did one hell of a job.
Mass Effect captures the very essense of space opera; all the mystery of exploring a galaxy full of aliens, ancient ruins and vast city planets. It is as scientifically rigorous as some of the best modern science fiction literature. It is as deep a setting, with as much potential for exploration and enigma, as Star Wars or Star Trek. It is crafted in such a way, that it is irresistable to long time fans of sci-fi, but also just as compelling to new fans.
The amount of minor detail that BioWare include, beats any other game by a mile. If the game world was not compelling enough by itself, with a detailed and awe inspiring history, fantastic alien cultures, etc, then there are even little tidbits of infomation scattered in minor planetary surveys:
An enigmatic terrestrial planet, Zayarter has a hazy atmosphere of nitrogen and argon. The surface is scorching hot, and mainly composed of calcium with deposits of sodium.
Three times in the last century, ships stopping to discharge at Treyarmus reported geometric patterns of lights on the dark side of Zayarter. Attempts at further investigation proved fruitless; the lights disappear when ships approach the inner system.
In just a few sentences, that come from scanning a random planet, the game has evoked as much mystery as some lesser video games do in their entire length. The game also contains an Codex, containing information that can be optionally read, detailing the technical workings of faster-than-light travel in Mass Effect, with as much rigour as a hard science fiction novel.