While the graphics, combat, and character classes are all excellent, the story is really what sets this game apart from other action RPGs. It is at least summer blockbuster caliber in scope and intrigue, and it will keep you engaged to the very end.The rumor is that Mass Effect is part 1 in a 3 game trilogy, and I cannot wait to learn more about the story and the game universe.
Despite the fact that there may be additional games in this universe, Mass Effect does not end with a cliffhanger. That is something I really like as I am not a fan of buying a game (or movie, or book) just to finish it and feel like I didn't get a full story.
You also really come to care about the characters. I am genuinely worried about which characters will make it to Mass Effect 2 (and 3) and what might happen to them between games.