Spoilers. Spoilers EVERYWHERE.
Here is my money / time no object rejig of Mass Effect 3. Some things to note:
I don't mention Starchild (much), Suicide Mission 2.0, choices not reflecting in the third game or the ludicrousness of basing your entire game solution on "Here's a magic space weapon, we don't know what it does or how it'll stop the Reapers and we'll keep drumming this into your head throughout the game because we literally have no sensible solution other than a magical off switch. If we tell you this enough times, hopefully you'll just accept and roll with it. Love, the writers". I already covered lots of those things here, so just assume all of that has been magically replaced - with space magic - by something that makes sense. Also Xzibit memes.
And here we go....
Don't place important plot points into optional DLC
1) As it turns out, the exploding relay in the Arrival DLC has caused lots of confusion with regard the ending of ME3 (did the relays blow up? a) Yes b) No c) Space magic). Worse, the supposed "trial" is completely absent from the start of ME3 so they can get to the shooty bang bang quicker. As a result, the start of ME3 makes little sense if you were expecting, you know, a trial sequence. There's no explanation whatsoever of why Shepard is even sitting in his room eating those three square meals a day.
Remove the railroading from ME2
1) "If you can keep up, great. If not, I'll stop the Reapers without you" I knew I'd end up going toe to toe with The Illusive Man when my totally Renegade Shep, who just gave TIM the Collector Base had the option of telling the guy he just gave the Collector Base to to "shut up".
My expectation before this happened would be that ME3 would have Paragon Shep working with the Alliance and Renegade Shep would be with TIM. The only possible reason you'd be forced into an artificial conflict with TIM would be if Bioware couldn't work out how to depict a conflict between small puny humans and 100 foot tall death machines in a satisfactory manner. I'm almost certain I won't be making this point later.
(Don't) take back Earth
1) "Take Earth back" is a great way to convince Dudebros and those unfamiliar with the series to jump on board because they're more likely to get that than "Take Thessia back", but as far as Mass Effect goes my Shepard has the familiar sensation of being railroaded into being some other Shepard again. Renegade, space born Shep who sent most of the Batarian race to their grave without a second thought and killed a bunch of other dudes in various hilarious circumstances couldn't give two tits and a monkey about a planet you've never seen for the duration of the series.
Also: it makes no sense that Shepard would be so desperate to have every species battle the Reapers on Earth unless there was some poorly telegraphed plot point from near the end of the game that would require them all to be there, despite them not possibly knowing at the start of the game that this would be the case.
I'm almost certain I won't be making this point later.
1) Having the invasion kick in right at the start of the game is a nice distraction for anyone wanting to shoot things, but the amount of exploration and questing related to your search to find a way to stop the Reapers is severely limited as a result. Everything boils down to "here's a big shooty battle, and now here's another big shooty battle". They should have taken the "up against the clock" mechanic of whether you saved your crew by going through the Omega 4 relay in ME2 and really thumbscrewed the player into making some desperate choices. At no point did I ever feel any dramatic tension, because it was clear from an early point in the game that I was just going to railroad through a bunch of main missions in an order I couldn't alter.
How much more interesting would it have been if you'd been on a set of smaller, more intimate missions as you travel to places like Thessia and Palaven to come up with some sort of solution to the Reaper threat? Instead, I got a moon that looked like Tuchanka with a colour swap and a railroaded chunk of Thessia that looked like it used Ilium assets without the purple light.
Intermission: Don't reduce dialogue to background noise
1) Not really relevant, but then again maybe it is. There's a whole chunk of game on Palaven's moon where you're just running through endless bland rock corridors to reach the next objective. The whole time, Vega and Garrus are talking and you're just running....and running.....and running to get to your next objective. In previous games, they'd have taken the time to take a breath, have characters stand around and just talk. Instead, the player is focusing on running - and this scene seems to take so long that I end up focusing on "Are we there yet?" instead of listening to the conversation. This is an awful attempt at giving dudebros something to do instead of immersing themselves in conversation.
The enemy of my enemy doesn't matter, have some Cerberus
1) Well, looks like I'm bringing up that whole thing about Cerberus after all. Not only does it make no sense as to why my Renegade Shep is instantly plunged into conflict with Cerberus in ME3, it also makes no sense that the "protectors of humanity" spend their entire time trying to kill the one man in the Galaxy who has proven himself capable of killing the Reapers.
How much of this game do I spend fighting Cerberus, being distracted by Cerberus. being foiled at crucial points in the story by Cerberus instead of, you know, doing something about Reapers? Why does this game have no primary antagonist outside of TIM? Why does Harbinger have this great build up in ME2, only to spend the entire game mute with a brief cameo, even though the original voice actor is in the game? "Harbinger speaks of you", says the Reaper on Rannoch. Well that's good, because he sure as Hell doesn't speak anywhere else. Tell him Shep says hi.
2) I'm going to go out on a limb here and suggest that having 100 foot tall death machines as a foe is only a good idea if you have numerous interesting ways to combat them. Given that the sole fight you have with one involves rolling around like an idiot while a Reaper with an aim so bad I can only assume he's a Stormtrooper, it would seem nobody quite knew what to do with the things. They're great at smacktalking you; they're good at telling you their goals are "beyond your understanding" (lol kidding); having a satisfying showdown, not so much.
See also: the Benny Hill chase on the Galaxy map. I was expecting something other than a game over screen to appear should you be caught.
So what do you do? Yep, have some Cerberus.
3) Kai Leng. You don't even get the satisfaction of winding up TIM throughout the game, because you get this lamer thrown at you instead. Bad enough he recharges shields by sitting out in the open, he only even takes out Thane because a) Shep & co have a bad case of cutscene incompetence and b) we're supposed to believe that the deadliest assassin in the Galaxy decides to go close quarters with a Ninja waving a sword when he's armed with a gun?
Oh God. No....just no.
Intermission: "They were gunned down while having drinks and watching the game."
FULL BODY ARMOUR AND SPACE HELMETS.
Multiplayer and variety
1) There's no way to know this for sure, but I tend to suspect that even accounting for basic reskins in ME1 and 2, the variety of enemies in ME3 is reduced because it's a lot harder to balance things in multiplayer if you have an endless amount of different bad guys, skills, stats etc. Better to have few guys from each group and be done with it. Of course, while this makes things more straightforward in Multi, it impacts on singleplayer. And it doesn't help that every other mission seems to be fighting Cerberus goons.
2) Hey look, another impact of multiplayer on singleplayer: poorly thought out battles. When almost everything in the game is shooting stuff, you'd better make sure the combat isn't predictable. A shame then that the combat in singleplayer often boils down to "fight three waves of goons", or "one of your squad has to fiddle with this button so now it's two versus about twenty".
Don't even get me started on that final shootout with the seven or so Brutes and the handful of Banshees.
3) As far as I can tell, most if not all of the N7 missions are just multiplayer levels with - you guessed it - horde style attack waves. Get rid of all of this.
Intermission: The Citadel is not the Normandy
Remember the Citadel in the first game, and how it was one big area and you could get lost? And how in the second game it was reduced in size to a sort of intergalactic shopping mall but still had a decent feel of "I could get lost here, and there's still a bunch of staircases"?
I've yet to see anyone point out that the Citadel in ME3 is pretty much the Normandy in structure and layout: a small collection of rectangular shaped boxes. I could be wrong, but off the top of my head the Citadel even has the same amount of floors. What went wrong here?
Intermission: What have we done so far?
1) Allowed you to side with TIM, or not.
2) Kept Arrival in the game rather than made it optional.
3) Delayed the invasion.
4) Kept the trial in the game, instead of starting it with a confused setup
5) Removed the focus on Earth because your Shep might not actually care, also horribly foreshadowed plot development.
6) Removed the conflict with Cerberus whether you side with TIM or not, because however you look at it this does not make any sense. This siding with one over the other should have affected gameplay and resource choices, not who you spend most of the game shooting at.
7) Made the Reapers relevant again by giving Harbinger his voice back.
8) Freed up resource by ditching the awful N7 missions. Goodbye forever, horde mode.
9) Ditched multiplayer, while I'm at it. I could be wrong, but I've yet to see Bioware mention that you need to do multiplayer to see Shepard survive at the end of the Destroy ending. This is all I can find.
Phew, that's a whole bunch of nipping and tucking. What now? Well, we assume the start of the game has better pacing and makes more sense. The first half of the game is Shepard & co finally getting to see all of the homeworlds you've wanted to explore since day 1 (with no corridor shooting, bonus). Then when the Reapers finally come knocking, the game would play out much as it did before I started typing because the "recruit the funny looking aliens" campaign worked fine despite my endless complaints over too much shooting.
Wind forward to the end of the game, which isn't focused on the Reapers anymore because in a brain straining effort on the part of the writers to try and think up a way to kill them we got that stupid kid, horribly circular logic and the knowledge that while Rannoch Reaper is allowed to comment on your (at that point) failure to unite the Geth and the Quarians, Shepard isn't given any dialogue option to point out that he did unite them both when the Starchild gives his speech.
But anyway. You heard me right, the Reapers should not have been the end of the game, the end of the game should have remained the Dark Energy threat raised in ME2. Everything would have come down to letting the Reapers harvest and look for a fix, or take them down then try to fix it yourself.
Rather than the "high level" Starchild, they should have been killed off with the somewhat more mundane (yet infinitely more believable) military might of your assembled armies. When I had to choose between Krogan and Salarian, I thought this is how it would go and my eventual alien race ally choices would save or doom the Galaxy.
Well, we know how that panned out. All the same, your choice of eventual allies should have been the dealbreaker. Not enough tech strength? Shepard doesn't beat the Roopers. Not enough brute force? Shepard doesn't beat the Roopers. A decent mix of the two but maybe one or more species had to bite the bullet to reach this stage? SHEPARD BEATS THE ROOPERS.
If you screwed up, everybody should have been squished in a tube and 50,000 years later we should have had a cutscene where some dude discoveres Liara's "warning: Repears galore" recording under a rock somewhere. If you got it right, you had a bunch of missions to solve the Dark Energy problem as per the ditched leaked script. Maybe there could have been an additional bonus where even if you allowed the Reapers to reap, they may have found a solution themselves after turning everybody into fishpaste based on if you'd done certain things throughout the three games. I mean, there's so many directions they could have taken this.
Feels bad, man.