Even though I still enjoyed it, I'd have to say Mass Effect. It had so much potential but ended up shooting itself in the foot far too many times. They put too much effort in the the universe/codex and not enough into the rest of the game that it turned out to be VERY AVERAGE. Now don't get me wrong, it was still a decent game, but SO much squandered potential. I enjoyed it enough to warrant me to buy ME2 and it's the only WRPG that I have been able to tolerate, but that isn't saying much. I'l break it down so the ME fan base doesn't crucify me and hopefully people are wise enough to understand.
Story: Holy shit did they screw up bad here!! Like I said before, they put too much effort into the codex and not enough into the characters and story itself. The main story was terribly short and had awkward pacing. Even though it was rife with sci fi cliche, it kept it together fine, but the stench of unoriginality still lingered. Pats of the story were not properly fleshed out, some went by too quickly, other aspects seemed to have no relevance at all. The story still held together fine but there were big chunks of wasted time and I could see the duct tape holding it all together.
The characters were both well detailed and...well...not. they all had decent roles and some had acceptable back stories, but their overall purpose to the story was shallow. I often questioned what purpose does this character serve in the overall grand scheme of the plot, but it just ended as them just being there "because". Just to offer you support in battle and to give some semblance of motive. Unless you interrogate each character, which is optional, big aspects as missing and characters have no value, I just couldn't care about them much because I didn't know WHY they were helping me. Saren as a villain had so much potential, but bioware decided to leave him out of so many instances and although i still liked him overall, he was terribly underused and deserved more encounters and screen time.
The main campaign like I said was short and felt over far too soon. Not many critical areas, and the overall story just felt lacking. It was hardly the paragon of storytelling people make it out to be.
Gameplay: It was decent and playable once you actually got good gear, but the difficulty curve at the beginning can be severely obtuse. Some enemies were a cakewalk while others would bum rush you and kill you without any trouble. Going off doing side missions at the beginning of the game can be fun and down right frustrating. The mako was fine, but it needs to be redone a bit as anyone who's played the game need not hear me rant about the mako. Planet exploration made up more of the game than the main story and thats a big no no in my books. Exploration was fine for the most part, but making a lot for the exploration point and click adventure games just squandered a lot of potential. Instead of "surveying" the asteroid, how bout I land on it hm?
Don't even get me started on the friendly AI. It was down right stupid at times although they DID seem to get smarter later on in the game.
There is also the dejavu of the game. There really was little mission variation, it was mainly go to planet, drive around, kill guys, raid warehouse, kill more guys.
Dialogue made very little impact on the game and only was there for the player to acquire as much or as little info as they wanted. Very few decisions aside from the obvious ones played critical role or altered the game greatly. There is no point to having choice if that choice makes little to no difference at all. Now I will hold some judgment of it when ME2 comes out and we see how many of your choices really do affect ME2. The Paragon and Renegade system did nothing at all, I hope ME2 takes it into account and makes something of it.
I still enjoyed the game play but it felt unfinished in many areas.
Visuals: Again a lot of dejavu. It was a very samey game. I can let the planets slide as they tried to go for a smi realistic universe and face it, most planets out there are desolate rocks. But why must every warehouse I invade or ship I board LOOK THE SAME!? Why must the architecture everywhere I go LOOK THE SAME. I know everything is supposed to be based off of prothean tech, but damn, you have all these races and worlds and everything LOOKS THE SAME. There was very little in the game was looked unique and made me feel i was on another world. I felt like I was simply globe trotting the same world due to architecture and everything being samey. Very lazy cut and paste design and that really detracts from making a unique universe.
Characters had good voice work but very little to no expression at all. Talk about immersion breaking when people have little to no expression in their physical features, it makes it boring.
Sorry for the mini review but I really saw a ton of potential in Mass Effect, but it ends up falling on it's face a lot and misses the goal line. I still oddly enjoyed the game enough to warrant me buying ME2, but there was a lot of potential squandered in Mass Effect that I hope is brought out more in ME2. So yea, lots of potential, but never quite reaches it.