Big Budget Movie Storyline, Excellent production values, dialog didn't get in the way (new for BioWare), and Fun!
Mass Effect was a true BioWare classic with a rich universe full of believable races. I loved the political intrigue both with the council of aliens, and the human dynamics amongst themselves. I also felt the interactions between teams were very exciting at times, I began to get attached to some and left others behind and not based on their skills but personalities which is rare in a game for me. The team combat was very fun and challenging as long as you played on the right difficulty level. The equipment was fun (although confusing at times). The leveling system was great for a few classes.
The Bad:
Like everyone else, the vehicle was so boring and overused. The planets all looked the same with different weather or colors. There was not enough variation in the universe of races, planets, and planet life (in other words planets felt to empty). Almost every time you did land on a planet there were just hostiles to deal with, very rarely did you discover anything that didn't have to do with war or battle (talk about hostile environment).
Overview:
Mass Effect took me on a journey that I don't think I could have ever anticipated. I was ready for it to feel like a star wars knock off, especially using the same dynamics as past BioWare games but it was truly unique in both story and challenge!
There was enough character development to pull you into their individual stories and you really did feel like a normal guy who made choices that ended up making you a hero. The game play was really searching to be a massive universal exploration game, but did fail in that. It felt like a very contained galaxy with a few planets to search as opposed to the 20+ galaxies that were represented with multiple planets that were just eye candy.
The story sometimes was too text driven (you found a pile of uranium so now you get so much money) and some of the side quests were so annoying that I can't believe they were included. Its like they had amazing writers on half the story and then their office workers did the rest.
The big picture is you can't get this entertained by most scifi movies out there, so its totally worth it. Whether you are a RPG nut or a 3rd person shooter buff, this has the right mixture between the two to keep you satisfied.