After going over several walkthroughs and bits of details regarding quests I couldn't complete and areas I didn't explore, part of me firmly believes the this game was a rushed product that suffered from two critical areas. The staff is largely different and the game has this pretty big imprint that it's designed to work for new gamers even in imports.
Evidence of being rushed
Scale
While the original Mass Effect had what many gamers called a dreaded driving sequence in the game, it did offer some distinct advantages to the game on it's own. For one thing it gave the worlds you visited a sizable scale rather than being restricted to a one-building setting. Noveria, Illos and even the side quest planets all offered a variety of different locals that were both expansive and interactive. ME2, while no longer essential parts of the game play, did have the free hammer head DLC, and incorporated it flawlessly into the "Project Overlord" DLC. In ME3, it's just a plain shooter.
Hubs
Probably the biggest missing piece of game play element was the variety of worlds Shepard could visit and actually interact with in a non-combat way. In ME2, there was Omega, Illium, the Citadel and the Shadow Broker base. All of these different locations offered quests, different shops and unique characters. In ME3, you only have the Citadel and stores that you don't even need to visit thanks to Cortez's shop on the Normandy. Plus putting everything on the Citadel can make things annoyingly crowded, which brings us to...
Mission System
Someone from the previous two games who knew how to make the mission tracking work obviously didnt return for this game, because the system is quite different in ME3, and none of it is better. To say that this system that keeps tracks of your mission progress is inferior to the previous systems is a gross understatement. I would say it's broken. When you accept quests from NPCs, it lists only the planet that the goal is located on where as in ME1 and ME2 it would list the cluster, solar system and planet. I had to look online just to finish half the quests. I didn't need to do that for ME1-2. And the fact that a vast majority of quests are handed to you on the Citadel either through direct contact or hearing some conversation makes finishing the quests a daunting task.
Characters and Plot elements that have been downsized or ignored
- Harbinger, a very vocal antagonist who was responsible for all the bad things that happened in ME2 is only rarely mentioned and doesn't have one line of dialogue in the whole game.
- Morinth, a former evil squad mate makes a return in the game's end not as a unique character that Shepard recognizes, but as a regular banshee with a simple name change and no dialogue.
- Hannah Shepard, Shepard's mother is only mentioned and has no speaking part. I LOVED her in ME1....
- Dark Matter Sun. During Tali's recruitment mission, she notes that the system's sun has been going through a lot of unnatural changes that shouldn't be happening. Several hints about how big of a deal this is are heard before and after Tali's trail, but it's never brought up again in ME3.
- The significance of saving/destroying the Collector Base. Only a 10 point difference in war assets.
- Shiala, a character who if spared in ME1, receives help from Shepard again in ME2 (with some hint at being a potential LI) is reduced to an email and war asset number.
- Rachni, a race of beings who Shepard could spare in ME1, swear to stand by and fight along side you should the time of war come in ME2, and only appear once in ME3 needing rescue AGAIN. After that, they're simply an asset number who are never seen nor mentioned again.
- Elcor tanks. Freaking let down of the year. The Elcor ambassador gives Shepard a quest to help evacuate his home world, but for some reason has you probe his home world's moon for an artifact instead. Despite how awesome canon mounted Elcor sounds, they are never seen nor mentioned in the final battle.
- Tali's face. Take comfort in knowing that BioWare dedicated more time and resources in bringing Jessica Chobot to life than putting in an ounce of work into Tali's face.
- Emily Wong. Death by twitter. Never seen nor mentioned in the entire game.