Mass Effect is a series I used to really love. I think I first played the original when I was twelve or so. And I still think its combat system is great, although none of the incarnations were perfect. But over the next few years I became extremely disillusioned with the intense statism in the game. In Mass Effect 1, you're a "Spectre", a special government agent with explicit permission to break the law in your service of the council. Mass Effect 2 is the least statist, but has that messed up scene in Mordin's recruiment mission where the guard won't led a woman into the district that contains her house to get her belongings and you don't have a choice to do anything about it. In Mass Effect 3, a big deal is made out of protecting the council from assassination, despite that even most statists could probably see how unjust this form of government is (the council positions are inherited by race and only the four most popular races are represented). In Mass Effect Andromeda, they go as far as having enemies literally labeled "Anarchist". Thank god, they're not actual Anarchists, just pirates.
This is far less important, but I also accuse the first three games of misogyny. Of most of the alien races, you actually never see a single female across three games. The Asari don't make up for this, and aren't the right way to make up for it anyway (they're a canonically all-female race with a culture closely based on human ideas of femininity). As a more minor point, in Mass Effect 1 all three of the women in your squad are recruited after saving their lives (albeit only one of them is a true damsel in distress situation). This is true of none of the men. Andromeda completely does away with sexism, but only at the cost of doubling down on the statism (see above)
Let me also make the case that all four games are heavily racist. There are a few facets to this:
The way the games focus to a ridiculous extent on humanity. In all of the games you're working for the human sub-government (except Mass Effect 2 where you work for an outright human supremacist organization instead), and you're mostly given missions that serve the interests of humanity specifically. Mass Effect 2 is all about the Collectors trying to make a human Reaper. Why? The only explanation that's even hinted at is Shepard. They thought that if humanity could produce an individual like Shepard, then there must be something special about humanity. Except that that's totally unreasonable! There isn't even anything special about Shepard in-universe. Mass Effect 3 is all about getting the races to work together... which of course means everyone pulling their forces away from their own planets to defend Earth.
Honestly, I think they should've made the player character an alien. Maybe not even have humans. Andromeda was a perfect opportunity to change to this since you're switching characters anyway. This is a huge missed opportunity to do something extremely unique and challenge the anti-alien slant that our sci-fi industry generally upholds.
The way the races are seemingly thought of by the writers as monolithic. The universe's history is filled with war between "the humans" and "the Turians", or between "the Krogans" and "the Turians". Have they forgotten that races are very diverse groups of people who have internally vastly different beliefs and values from each other? You would never have a war between two entire races in real life. I looked at the Mass Effect wikia to refresh my memory, and neither war was believable. The First Contact war started entirely because of a misunderstanding before the humans had met the other races where Turian enforcers shot down human ships for violating a law they couldn't possibly have known about. When the human government decided to respond by declaring war with an alien race they knew nothing about, what did they think their odds of winning were? The Krogan Rebellions apparently started with "the Krogans" invading other races' worlds unprovoked. If that were the case, surely many (if not most) Krogans wouldn't have participated in the ensuing war, or would have even fought against their own to protect their race's galactic reputation.
Finally, and most generally, the intense in-universe racism in the way the races feel separate from each other is fine as a world element, except that none of the story focuses on challenging that. When you put racism in your universe and make four big RPGs in it each with dozens of quests and you never let the player seriously challenge the racism, you're validating it.
As for the plethora of plotholes in Mass Effect 2, 3, and Andromeda, I can't possibly say it any better than Shamus Young did (the link is to a 75-part review that covers all four games in detail). I didn't even notice most of the plotholes he points out when I played the games. I think I played the last of these games when I was about sixteen, so before I developed my modern philosophies on storytelling.
There's also the pitfall of fake sci-fi, of course.
Okay, so now that I've hated on the story and world enough, I'm going to discuss what's good about Mass Effect: its combat. I do believe it is a genuinely good team tactical shooter. The concept of powers is really innovative; it adds so much more depth and tactics over a game like Call of Duty where all that matters is your aim and taking cover. And I especially like the idea of being able to pause a real-time system to think. I don't think this couldn't have been improved by making the ability not unlimited, but it makes it feel like the perfect mixture of Telepath RPG 2 and Republic Commando (if you don't know those games, just substitute Chess and Call of Duty). The Mass Effect games were very fair and fun to play on the highest difficulty, especially Mass Effect 2. (Mass Effect 1 insanity got too much of its difficulty from overstatting the enemies defensively, and 3 and Andromeda were honestly too easy on insanity.)
There are a few more things I want to say about the pros and cons of each implementation of the combat system. Mass Effect 1 was my favorite (but just barely). I liked that it had separate power cooldowns (so you're incentivized to use them all instead of just spamming your most upgraded one), and I also liked the diversity of the powers. There were so many different kinds: disablers, damage-dealers, defensive powers, weapon powers, you name it. But in 2 and 3 most of the powers do basically the same thing: damage. The only difference is which type of defense they're good against. Powers like Throw, while they still exist, were pretty useless in my experience because they only work on unprotected enemies (and when Throw does work it still seems to do more damage than debilitation). That said, I definitely liked the later games' idea of letting you wield any type of weapon instead of being limited to the pistol if you're not one of the Soldier classes.
The revive system is another thing worth talking about. In all the games your allies go down frequently and there's sometimes not much you can do about it. In Mass Effect 1, you can use the Unity power to bring them back up, so it's not a huge deal as long as it doesn't happen more than once per fight. Of course, the cooldown was ridiculous. That game was terrible about incentivizing you to wait between fights. In Mass Effect 2, it's a bigger problem because you have to use limited medi-gel to revive them (which doesn't even fully regenerate between missions!). Mass Effect 3 finally fixed the problem for good by letting you revive your allies manually. Mass Effect 3 still has the limited use medi-gel ability, but manual revives are a more dangerous, more rewarding option. If only they had made the game a little harder to compensate...
Also, the equipment system. In Mass Effect 1 it was always more drudgery than fun. You find a new gun in almost every room and you don't care enough to look at it every time. In Mass Effect 2, they overcompensated by pretty much completely removing the equipment system. It was bad, yeah, but there wasn't nothing to be said for it. It did add some customizability that was useful.
Mass Effect 3 was the perfect balance. You don't find new gear everywhere you go, it doesn't take that long to configure, and there are some legit meaningful decisions to be made with it. But then Andromeda comes along and... god, no, you gotta be kidding me. I have to loot bodies now? What the hell! Just because Skyrim did it doesn't make it right for every game! If there's no reason why I wouldn't pick up the loot, then Ryder should do it automatically.
Well, it's been fun ranting, but I guess I'm done now. Stop reading game reviews on my site and go do something with your life. I'll set a good example for you.