The combat's clunky, the environments are dull (some of the times) and the urgency you're on about is kind of thrown out the window when I'm killing mercs for medi-gel and ****** around with my MAKO.
You make good points, like always, but stuff like chest high walls (still present in ME1) and corridors don't bother me as much as they would do to other people. ME is a shooter, from start to finish, no matter how much you cover it up with RPG mechanics and "tactics" it's still a damned shooter.
At least its better than recycled environments and a game that's literally impossible to play on insanity because "I'm going to use this one skill that makes me invincible for a long time" which just slows things down unnecessarily.
ME can be the action game it wants to be all it wants as long as I get to choose what Shep says.
The plot was a giant side-mission, yeah, and it pretty much screwed up everything despite being fine on its own.
And TIM was cool.
It's nice having an antagonist who's also your best means to survive. Nice twist to it.
Actually there aren't any apparent chest high walls in ME1, there are walls to take cover from, but rarely any actual chest high walls, and given the combat isn't build like your average Gears-of-The-Last-Uncharted-based shooter, that makes it hard to label it as such; For instance, if you actually want to take cover from the occasional chest-high-wall, then you have to press a button to make your character bend their knee then lean against. It was unintuitive as a cover-based-shooter, so I say it's easier to label it an action game with RPG mechanics. The combat wasn't perfect, however, but I kinda preferred it over the dull shooter mechanics of the second game. The reasons as to why is because in retrospect, I could shoot my way through ME2 without having to actually worry about setting my skills. There aren't any real actual RPG mechanics. ME1 & Alpha Protocol both share this principle of having RPG mechanics factor into conversation and combat alike, along with the combat not being the best, but at least they account for the fact that you aren't instantly able to shoot the on-button on a tumble dryer, from a few miles away. In ME2, you could play as a Biotic with a Sniper Rifle and they'd instantly know how to use it. You wouldn't necessarily need to ever level up your skills because you could beat the game just as easily.
As for the first point you made -- Well, it's hard for me to argue that there aren't a lot of side quest in ME1, as well, that ultimately'd take your time away from the main plot for a moment, which is true, but that's generally an RPG thing, right? You'd think Geralt of Rivia would have better things to do then running around picking his nose the first 2 hours of the Witcher and Witcher 2, before the plot finally decides to move on, because of all the fetch quest (mostly in Witcher 1) which is why that game bored me a lot... until I played it again and it finally became halfway engaging at least after 7 hours of doing dull stuff.
But in general, I'd still say that during the main plot of ME1, I still felt that urgency, as opposed to just running around saving remote human colonies in ME2, while occasionally doing the most uninspiring linear side quests. The environments of ME1 might not have been perfect, but I found there were more engaging side quests than "land on this planet, shoot some mercs, report to Cerberus, repeat". ME1 had those too, sure, but some of them did have some half-way engaging backstory as well, like the ones that dealt with Shepard's background.
One thing I'd also argue in regards to Mass Effect is the sudden shift in tone. In the first game it felt closer to a sci-fi-epic-opera, whereas in the second game it moved closer to that of action-sci-fi film ala Total Recall. This is reflected in the game's pretense to being more edgy, in terms of the dialogue, pacing, tone and even gameplay.. like Shepard's sudden raspy Dirty-Harry disposition towards NPCs, sometimes punching them, shooting them in the head, or spouting whacky one-liners akin to that of 80's b-movies. The characters are also more akin to swearing every now and then, which kinda felt a bit weird to me, but this seems to have been an overall change in BioWare's design approach, cause that's how it is in Dragon Age as well.
I feel the changes in the gameplay is probably a factor as to why the game seems to have built itself around its heavy-shooter-mechanics, thematically and tone-wise notwithstanding.
The reasons why I didn't like the Illusive Brah, or at least one of many reasons, is because any pre-emptive neutral-common-goal-intentions he might have had felt somewhat inconsistent with that of Cerberus' backstory, as it was established in ME1. Finally you have his continuous attempts to try and get you killed, or constant spouting of platitudes in regards to the horrible things his organization keeps committing.
Lastly, I mustn't forget about the start of the game. Shepard's death is so incredibly obnoxious, because it's essentially set-up as a shoe-horned mechanic to reset your character from scratch and introduce the Thermal Clip System -- It doesn't help that in-game it's also pretty much played for ****'s 'n giggles. Shepard: Oh, I've been dead? Cool. After that it doesn't take long before the whole thing becomes the subject of all the character's jokes, not really much else to it -- it felt so token and unreal. It'll be like if Geralt lost all his memories, again, in Witcher 2 and had to learn them all, one more time, though he already has his swords and signs by the start of it. Now he'll be able to developer further; That's a much better prelude to a sequel with the same protagonist (even if I don't really like him).
There's something I think Mass Effect 2 did better than the other games and that's the DLC. The Shadow Broker DLC actually felt like it added something to the game at least, the one with the rogue AI brought (somewhat) back the chance to explore a planet although not really-- but there was some good atmosphere in that one that I liked. Other than that, I don't think any of the Mass sequels did much to engage me.
Anyway, thanks for appreciating a nice discussion. I also think you made some good point as well in regards to combat mechanics, which I also made sure to address as well as best as I could 