Well...
1- Gameplay: it has always been secondary to me, but I think it's smooth, has pretty good kombos and animations, I can have fun with it.
Shinnok has too few kombos, just like Scorpion, sometimes that's bad (for Shinnok, for exemple).
2- Story: with a cool head, more foot to the ground to say.
Mostly I liked it, IMO they made a good connection with MK9.
As said by fellow users above, Outworld's civil war was pretty much bad explored.
The game itself could have spared Earthrealm from becoming an eternal camp of invasion and center on Outworld, and they could have done it without going away from their idea, except for the obvious Jinsei (which is a very good idea about life of the realm, IMO).
I liked how the plot has evolved, I liked the new characters, I absolutely loved the ending.
Scorpion: pretty nice twist, but, in the end, they made him do some BS as always.
Sub-Zero: wish I've seen more. Thank Elder Gods, human again.
Raiden: too absent of the story, possibly to balance with his latest appearances. Won't add here at all (remember that I said that it was a "cold headed" comment) that I thought he should have beaten Shinnok (passionate comment).
Cassie's victory: to tell you the truth, I don't think MK fights are based on strenght, but skill, and I'm not saying that an Elder God doesn't have more skills than a 20 year old human, but, you know, chances are chances.
Kotal: as said about Outworld, I think that in the end he acted like dumb. They should have let D'vorah's allegiance more clear to him.
Erron Black and Ermac: little screentime, if Outworld had more attention...
Johnny & Sonya: too much complaints, but none from me. Never cared about both, but I liked them in MKX. Seriously, they were "Adam and Eve" of MK9, it was obvious they would play major roles. Finally Cage got a little more serious. Sonya looks pretty badass. About "just humans", well, they are not like us, right?
Shinnok: absolutely awesome, he was what he should always should be. Not very climatic ending for him, but extremely good entrance. Showed himself as a true boss (story).
Revenants: I'll show more of my opinion later on roster topic, but inside the story, Liu Kang was awesome, still, I expect a future about Jade. Nice to see Sindel and the other NPC again.
3- Roster: You know, the same way they could have given more attention to Outworld, our roster could have been differently.
Revenant characters should have been the big surprise. I hate those old versions, what ifs that scammed us all, in the main roster.
Liu Kang, Kitana and Kung Lao should have never been in the MAIN roster. Unlockable? That would be the best. DLC? Maybe. But never older versions that serve no purpose.
The story have dealt with quite few villains, since the story basically make Outworld as neutral. In the end, we had 1-3 villains, and one of them absorbed the others.
We discussed many things about characters like Reiko, Havik, Onaga, etc., they could have served well MKX, but let's talk about'em more o next topic.
4- Komics: Look, when I firstly put my very eyes into the komics, I loved them.
I felt Kittelsen was a good writer, he indeed is, and everything was fine.
Then, the game came out.
Seriously, I pretty much don't care about anything outside the game.
Now, looking to the whole ground of MKX, I can say the komics suck so hard, they are inconsistent, incoherent, they kill every millimiter of canon and of the story.
I know we have changes, but dude, the comics simply pick a character, ignore their very substance and start inventing a lot of BS.
They created an idiotic story about blood, put the One Being in it, then said it was Nitara, gave Havik lots of powers totally outside his character, created a possibly promising Reiko just to kill him in a very anti-climatic way, expressely destroyed Onaga's origins and give me the feel that Kittelsen is there just to erase what we call 3D era.
It seems NRS gave Kittelsen freedom to erase everything, and most MK fans are so desperate to see their favorite characeters that they just don't care if they are coming in a distorted and incoherent way from the original, also, considering the number of chars, many fans simply don't care about coherence of the whole plot, and discard those that they dislike/don't care/are neutral, but in the end these changes complicate the whole story.
Many komics were pretty bad drawn, and Kittelsen himself says to be a MK fan, but, seriously, I really doubt how wide is his knowledge, judging by how he destroys the characters. Pretty easy to earn money like this, I pick up an original creation and start doing my stories inside the universe of the original creator and changing the characters the way I want, without any care about harmony.
I will repeat: MKX komics are FORMALLY canon, because Boon said it. Essentially, it's absurdely non canon, but market speaks louder.
5- Kombat Packs: The first one looked cooler, Jason was announced before, so I thought he would be the only guest.
Then came Predator, well, I really like the character, but I will always expect and want more MK chars, whatever market speaks.
Tanya and Tremor were well added.
Then came KP2. Fujin was highly asked, his story appearance was pretty good, and we do have some MK chars on story.
Nope. We got Bo' Rai Cho (expected, those farts on a Kombat Stream, and he was in the story, needs more justice)and Tri-Borg (I must admit it's a pretty clever idea, I wanted Sektor back, Cyrax was welcome, but the random Lin Kuei...I assume it's not Smoke for obvious reasons) from MK. Then, instead of genuine MK chars,we got two (IIIIIIMMMMMMMOOOOOOO) unnecessary guest characters. This is MK, not AvP.
But we can't pretend there isn't people that like guests, even to the point to make a new Marvel vs Capcom inside MK (sales, right?), but it's annoying that they mix this what ifs fan fictional things into MK chars. I seriously believe there should be guest packs and MK character packs. Every guest that is added to a KP means, to me, -2 MK characters.
Notice that we could have, despite the clever idea, Sektor AND Cyrax, but they put both into one, and a random-dude-that-if-it's-Smoke-then-What-If-went-beyond-measures, just to leave two spots for guests. Imagine, when they put Ronald McDonald and Bozo in KP3, maybe they want to put more one guest, so they could make one MK character that every variation is another. Don't doubt it.
So far, that's it, I have much fun with the game, love the beginning, enjoy the course, love the end of the story, dislike the comics with every canon corner of my existence, dislike too many guests and want more MK inside MK.