This game made me feel full of wonder and discovery as I played it. I consistently found brave new worlds and whole new frontiers to explore. I was already enthralled from hearing the menu/Vigil theme in the beginning, and the music didn't let me down from there.
In this trilogy, you are Commander Shepard: a seasoned galactic marine who knows his way around a shootout. The plot itself is too hard to explain in this post in much detail. You gotta know about the many different factions, species, and technology in the Codex to get a good look at the whole picture without being stumped. The simplest way to put it is that due to a series of events involving an ancient species of advanced aliens that disappeared, Commander Shepard is forced to launch an expedition across the galaxy to capture an interplanetary terrorist of galaxy-wide repute, amassing allies of all kinds of repute and designs along the way.
This game was built to have vast, beautiful landscapes from beginning to end. And it damn well better considering the ridiculous amount of time that's spent driving around in the Mako doing nothing. I honestly did not hate driving the Mako until I got around to the end, and by then I wanted to flip it upside down out of spite.
As for characters, every team member was easy to get along with, and I had love for everyone in my party. Except for Ash. When put on the spot to choose a partner to romance, I chose Liara without hesitation. Ash having bunned hair was just a dealbreaker for me. And then I left her to die on Virmire, because I liked Kaidan more. So I broke her heart and then got her killed, and it was one of the funniest moments I ever experienced in a game.
I had only one regret for a character that died (Other than Jenkins, rest his future soul). I sincerely wish I could have saved Saren, because he really didn't deserve to die like that. I finally broke through to him and temporarily severed his Indoctrination, only for him to shoot himself in the face and be revived as a mindless cyborg and final boss. It was truly heartbreaking when I thought back to it in Mass Effect 2, because it was actually a very serious achievement to have broken through Indoctrination like that. After saving the Council and placing Anderson as the voice of humanity, I felt like I did a true amount of good. But by the time I hit the second game, I'm really starting to wish I let them die.
I played as the Soldier, so my versatility with guns was unmatched. I always play as the Tank in my first playthrough of an RPG, so I was a hell of a damage soaker. My favorite guns to use were the Assault and Sniper rifles, since my play style involves precision shots and maximum spraying for maximum damage. Another aspect that I found interesting in the weapons of the game was the cooling and overheating mechanic, and I'm actually pretty sad to see that it was disavowed in favor of traditional ammo-based guns in the sequel.
As always, any enemy that shot back was a joy to deal with. I usually settled my problems diplomatically whenever I was given the opportunity, but if the conversation ever went in the wrong direction I always had a gun to make cooperative corpses. Zombie-type enemies like Husks or Thorian Creepers were way less fun to deal with, though. Shooting a running madman who has no attacks other than to claw through my Space Armor is boring without having an actual threat.
On the subject of bad aspects of the game, the running speed in this game was a snail's pace, with barely any stamina for sprinting. Sprinting can only ever be done while in combat as well, which was another gripe I had. I also really wish the game came with a "Press here to smash face" button, because a Melee command would have come so very handy in the Zhu's Hope campaign thanks to my unskilled use of Thorian-Grenades. The game also had an extremely frustrating habit of COMPLETELY AND ABRUPTLY FREEZING DURING LOADING SCREENS. Seriously Bioware, What the hell?
The exploration aspect of the game is what kept me going, even when those collection sidequests were at their worst. Finding those Heavy Metals was a pain in the ass; but I'd do it again just to see how it affects the future.