IN ORDER OF IMPORTANCE (top being the most important)...
1.) No Input Bug
2.) All mids/overheads hit on ALL character's crouching animations (this includes on their crouching attacking moves too, to prevent unnecessary whiffs)
3.) Enhanced online (PSN still needs connection indicators to tell us who has a 4 bar or 2 bar connection BEFORE we submit a challenge request and/or accept one. by default it constantly says everyone has a 4 bar connection...which is far from the truth. this isn't an issue in KOTH though :/ )
4.) Strengthen the weaker characters/More overall character balance (for a game like MK, I wouldn't be against characters having different amounts of health....could be a huge way to balance out the game. Especially for a character like sheeva...how she is currently :[ )
5.) Reduced invincibility frames of wake ups or make them cost meter (I can't stress how retarded it is, that once I score a knock down in this game, I can't capitalize on it with oki/more pressure. it's the dumbest thing I ever seen, and MK is the only fighting game with this. a character...like sheeva, for example, who has to work so hard blocking correctly while dealing with pressure and/or being zoned half to death *due to her hassive hit box*: should, or has to - be rewarded for a successful knock down. IT'S DESERVED. and wake ups, how they are currently...disrupt it. I don't mind wake ups to be in the game *they're in every fighting game*...BUT ONLY COST METER *the good ones in most fighting games cost meter*. It'd add to the meter management. and would encourage for it to only be used for an emergency "back off me move". thus most of the time when players score knock downs, their opponent has to guess and deal with the mxup/pressure...as it should be IMO)
6.) Remove dial a combo (it's the scrubbiest shit ever. i'm not saying that attack strings need to be one frame links like in SF4 series, but I am saying the timing needs to be more strict in sequence. this would help in encouraging hit confirms too)
7.) Remove negative edge (negative edge really gets in the way of players trying to play at maximum speeds depending on their exact execution. and there's no character in the game that needs to depend on it, because there are no charge attack button inputs *press hold release: example Eddy in Guilty Gear Series* in this game)
8.) DO NOT REMOVE CHARACTERS FROM THE GAME (this is something I really hope NRS reads. NRS has spent so much time improving the game and balancing out the cast...that removing characters for the next game/installment would be counter productive. just simply not include the older characters in STORY MODE if need-be. but allow them for every other mode in the game. even if you have to release the older characters as DLC....DO NOT REMOVE THEM FROM THE NEXT MK GAME)
9.) DO NOT REMOVE TAG MODE FROM THE GAME (I really don't understand why we're not playing this mode more often in tournaments. there are so many things unexplored in this mode...that people simply write it off unbalanced....BECAUSE IT WAS UNTESTED. very sad. now a days, fighting games are gaining more popularity/hype because of tag/team/Assist based system mechanics *SFxT, UMvC3, KOFXIII, TTT2, Persona 4, etc.* and MK could very much increase it's player base if Tag mode was more encouraged on a competitive scale. it's STILL NOT TOO LATE FOR THAT, but no one is doing anything about it. anyways, I for one, would love to see Tag Mode return in the next MK fighting game. Tag combos are MAD HYPE IMO)
10.) Increase overall background music audio (it's really hard to hear the BGM for this game. transitioning from MK to a different fighting game...in terms of sound...is like night and day. i'm sure other people notice this too :/ )