My biggest complaint so far is the apparent glitchiness of Shao Kahn, on multiple levels.
First and foremost, there seems to be this "screw you" AI that inhabits Kahn the first time I've fought him going through the ladder with the first 19 characters I've beaten it with (I'm going one by one in order in the character select screen). I believe I've managed twice (one that I remember for sure) to only lose 1 round to him when not having previously lost a single round the entire ladder on Medium. That was with Scorpion (the other maybe, if I remember correctly is Sub-Zero). I've yet to be able to beat him two rounds in a row the first time through. I still have 9 more characters to go so there's still a chance, but I guess its less to do with me feeling like I've legitimately been beaten and more so to do with the, what I refer to as glitches, below. Also, most times (with a couple of exceptions where its taken me 3 or 4 times), the second time through I completely demolish him.....using the SAME strategy. Its just little things here and there in the first match that point to the AI purposefully increasing its difficulty through nefarious, cheap means to thwart a legitimate two round victory.
Glitches -
1. Problems clearing Hammer Uppercut - There's vast inconsistencies with how this move hits a character. Some characters I've just started to leap over Kahn as he's beginning the animation. It seems delayed enough to where I should get hit, but instead I clear the hammer with the cross jump, landing safely behind him for an uppercut. Other characters I'm already fully in the jump motion before he starts the swing, yet I'm hit at the peak of my jump by his uppercut instead of clearing him where I feel like I should. The hit detection with that movie is definitely wonky and needs some tweaking to be more consistent.
2. Problems clearing Kahn jumping - Occasionally I will jump from a distance that appears to be a normal distance to jump over Kahn, yet I'll hang seemingly above him but just in front of him and fall right in front of him for a big hit. This doesn't happen very often, but when it does, it really leaves you defenseless for huge damage. It just looks like its incorrectly detecting collision where there is none on the screen.
3. Problems with Kahn not auto facing the proper direction - Frequently (on average at least once a match and upwards of three or four times) when cross jumping Kahn while he is not down, he will not auto face your character when they have cleared him or when they land behind him. Instead he stays faced the opposite direction. Where this is a problem is trying to bait him into an attack for cross jumping behind him for an uppercut. No other character in the game that I've seen exhibits this behavior and its uncommon enough to lend credence to it being a bug more so than just part of a battle with Kahn.
4. Problem with hit detection of uppercuts - I can count on both hands the number of times I've been standing right next to Kahn after a cross jump, have uppercutted him, and whiffed. I don't mean he turned and blocked it. I mean it completely missed him while he was unprotected and not ducking.
I expect Kahn to be difficult, but the above are legitimate, real problems to an already super aggressive AI. Again, these seem to crop up more the first time fighting Kahn than subsequent fights. The point is, they shouldn't crop up at all.
I don't really anticipate these being fixed as these are minor and by no means make Kahn unbeatable or broken. They're mainly just nuisances. But it'd be nice if they did address them.