Mass Effect Andromeda is a game that isn't nearly as bad as the internet would want you to believe, but does have a lot of issues. Sadly, a lot of those issues could have been avoided.

Some mechanics are actually pretty good. Combat itself is the best it has ever been in the series. Too easy later on, even with on the highest difficulty, but a huuuge step up from the awful combat of ME1 and ME2. (In that regard, in case anybody says combat in ME2 is good, start ME2, pick adept without taking Energy Drain and do Jack's retrieval mission with Jacob, Mordin and without fancy DLC guns. ME2 combat was better than ME1, but still suucked). I wished we had a bit more enemy variation - there is no difference in how you tackle each faction - and melee enemies are useless thanks to our jumpjets, but it is solid.
This can be improved with mods.

We have bossfights now. That's new. But it's always the exact same boss, so... why?
This can not be improved with mods.

Graphics are stunning, but at the same time are a huge resource hog, but that's normal for PC games.
This can be improved with mods.

Animations were bad, and justly criticized on release. I only got the game later (why people still buy games from publishers like EA on full price is beyond me) when there were quite a few patches, and it was okay.
This can be improved with mods.

Item management gets a huge plus for all the different guns and armor... and a huge minus for the fact the huge amount of junk. Crafting us kinda stupid. You simply pick what items you want to use, and every 10 levels craft a slightly better version. What is the point?
What is the point in looting and buying items of the versions you craft are always better (more slots)?
What is the point of all the different recipes if you already know them and simply have to unlock them? This would be a lot better (and more logical) if the crating recipes (at least for non-Milky way stuff) were loot to find. That would actually give you a motivation to hunt items.
This can be improved with mods.

Driving around, exploring planets is the best it ever was. In ME1, each system had exactly one planet to explore... which, most of the time, were 2-3 pointless anomalies and lot of awful, tedious driving.
This can likely not be improved with mods.

We still have minigames. Not sure, because 3 was fine without them, but I personally like Sudoku, so that's okay.
This can be improved with mods.

The Apex system, multiplayer integration and the unlocking of perks via readiness meter... is a thing, I guess. It's pretty pointless, but gives you bit more to do, I guess.
On the plus side, it did give me inspiration for a yet-to-code feature, so yay!
This can perhaps improved with mods, but not much apart from mild number-tweaking.

Multiplayer... exists. With lootboxes. It's a carbon copy from ME3 mutliplayer that somehow manages to be worse in all departments.
Perhaps this can be improved with mods, but really, why bother.

The voice acting ranges from good (I didn't make these mercs because I hate the voices ;-) ) to godamn atrocious. Like weapons-grade awful. Most asari and salarians sound like they are out of some saccharine Disney kids show. On many worlds you will find NPCs with lame dialogue, voiced so boring methinks they cut the budget in this department.
This can be improved with mods, but that would require actual voice actors.

The writing is baaad. Like, really bad. Really bad fanfiction bad. This is the bay of pigs invasion of plots.
Nominally, this is the story of a marooned group of desperate survivors in a harsh galaxy, bereft of hope, out of supplies, scrambling together in a desperate effort to establish in a new and dangerous galaxy, against hostile aliens, harsh surroundings and inner turmoil.
Instead, we get:

• A lead character comically unfit to lead, propelled to this position by laughable nepotism. This could lead to an interesting story, where we have to grow and become the leader we should be, but... that never really happens. Some characters simply are a dick to us, regardless of what we do. Our second in command - WHOSE POSITION WE BLATANTLY STOLE - has no problem with this. None whatsoever. And we're never called out for this shit.
• Our close companions range from (admittedly, well-done) copies of previous characters (Drack, Vetra) to a complete mess (Peebee) to whatever the hell Liam is supposed to be. Like, Idonteven.
• We establish out oh-so desperately needed colonies by doing a bunch of fetch quests nobody else could be bothered to. And solving Sudoku puzzles some ancient bots left behind. Sudoku is important.
• The logistics behind this endeavour makes no sense.
• New race #1 is the result of someone wanting wanting a Prothean like machine race, but as boring and generic as possible.
• New race #2, the generic bad guys, are a copy of the Collectors, just more generic.
• New race #3, the generic good guy race, are... there, I guess. They posess no individual traits whatsoever, contrast to existing races. The game says they are oh-so emotional, but react to two plot points that should friggin' rip their society apart with less emotional outburst than I have towards bowel movements.
• The fact that, well, we are for once the aliens invading another place, is not used. The only ones hostile to us are made clear to be bad guys, so we can shoot them and feel good about it.
• The game quickly establishes that you are the chosen one, due to your ability play uplink to Siri.
• The expedition sends out 6 ships. It is required that they work closely together. Naturally, they are sent out alone and at different locations.
• The colonisation effort apparently had a huge number of violent outlaws, because reasons.
• We are the only person in this galaxy with Sudoku skills.
• The motivation and reasoning of your superior officers changes between sentences.
• When asked what motivated them to leave their lives, family, friends etc. behind, everybody gives an answer about as convincing as Herman Cain's position on Libya.

It gets even worse once you consider that this plays in the Mass Effect universe:

• Mass Effect is (among other things) a series about an eternal struggle between organics and synthetics. The main conflict is with a mythical race of machines that kill everything. Throughout, you fight machines and others brainwashed by those machines attempting to kill everything. Numerous times, machines rebel and try to kill everything. Like, say, that one time in ME2 when a scientist embeds a machine in his brother's head, which goes bad and kills everything.
  
  So naturally, the protagonists father plants a powerful AI in our head. Which, despite what we are told, can kill us comically easy.
  Naturally, our main character thinks THIS IS THE BEST IDEA EVER.
• The people in this game left the galaxy between ME1 and ME2, so shortly after the synthetic geth attempted to MURDER AND KILL EVERYTHING IN THE NAME OF THE MACHINE-GOD. They also DISMANTLED A MASS RELAY AND MADE A TELESCOPE OUT FROM IT, and told us they found a totally safe galaxy we totally should settle.
  Naturally, we did just that.
• At the time, many turians were still debating whether it wouldn't have been easier to just bomb these upstart humans into oblivion a bit more.
  We somehow get along just swimmingly.
• Everybody kinda agrees that Krogan are a brute, extremely agressive race.
  Naturally, we made sure to take along a lot of them.
• Our second in command is named Cora Harper. Seriously, wtf?
• Apart from our squad, which is regularly on side missions, the not-the-Normandy has... 4 personnel total. Soo... if Kallo needs to pee or go to sleep, we just activate the auto-pilot?
• The link between the cockpit and the rest of the ship is a thin glas bridge without rails.
• The Nexus has a scout ship, but waits using it for 14 months, because they had nobody as awesome as us to stand around on the bridge.
• Remember the krogan genophage? You can cure that by just sleeping 600 years, because that's how genetics work.
• When you pick up a homicidal AI that tried to kill everything, be sure to store it next to to the AI core of the powerful AI you already have, no supervision needed. That worked well in ME3, it will work well here.
• If you played the previous games, you will surely remember how absolutely swimmingly the races worked together by seeing how well they work together here.
• Remember Conrad Verner? His sister is here, to pursue her dream career of... being a dancer in a shady club. *cause that wouldn't have worked in the Milky way.
• Remember Zaeed? His son is here, to pursue his dream career of... being a grumpy merc. 'cause that wouldn't have worked in the Milky way.
• Remember Okeer? One of his scientists is here, to pursue his dream career of... experimenting with shit to cure the genophage. 'cause that wouldn't have worked in the Milky way.
• Remember Garrus? We stored some audio links to him, so that you do.
• Remember Liara? We stored some audio links to her, so that you do.
• Remember the Reapers? We stored some audio links to them, so that you do.
• Remember how you can just decide on a whim to be a biotic? That was totally how it worked in previous games, right?
• Your characters is meaningless. You are effectively a slave to the personality-free AI that daddy planted in your skull. You are its slave, and you will crave its witty banter, biatch.
• In a game rightly criticized for its bad facial animations and voice work, Bioware somehow did not include Quarians, Volus, Elcor and Hanar.

I could list, a lot, lot more of this. I think you get the idea.
This can not be improved with mods.