I would keep:

1. Gameplay Engine
-The gameplay felt the best out of all the 3D MK games, so no need to waste time coming up with an all new engine. Just tweak the one already there, and just apply polish anywhere needed to make it run smoother.
2. Freefall Kombat
-This seemed to fit in well during transitions, and I don't see the harm in making that part interactive as opposed to not.

I would change:

1. Make it darker.
a. Gore:
-I know it was going for a T rating, but this time around I want it to be dark, edgy, gritty, and shocking. MK used to set the standard for violence and edgy themes. What's considered "dark" and "violent" has changed since almost 2 decades ago, so it's time to ramp it up. I want to see dead bodies throughout levels. I want to see blood used in all kinds of ways, but only where it's effective, not just for the hell of it. Dead animals, dead children, dead babies, severed limbs, people hanging, skeletons, crap, vomit...I mean anything. Make it make sense though. No 10 torsos sitting in a room for no reason other than to be "scary". I want to feel bad about playing this game.

b. Levels:
-I want the level design to be creepy and dark. I almost want to say the word "distracting" to descibe how they should be. Environments that make me want to look around as I figh. I want it to make me feel nervous, uncomfortable, and eary just looking at the background as I battle my opponent. I want slaughter houses with dead animals, prisons where the inmates are spewing curse words and throwing fecal matter, insane asylums where they are killing themselves or sitting in corners talking to themselves, morgues with dead bodies and an incenerator, battle grounds with piles of bodies on fire, wastelands with skeletons of animals and people etc. This is some creepy shit. A graveyard with a moon shining down and some tree silouettes just doesn't cut it. Not to say you can't make something like that creepy, but they are way too clean and bare to make it truly unsettling.

c. Fatalities:
-I want to see some really fucked up stuff along with what we normally get. I recall seeing Reptile eat someone's face off in MK4 and thinking "That's creepy." More of that please. Kano ripping out someone's heart, and then either eating it himself or shoving it into his opponent's mouth. Tearing someone's jaw off. Cut their tongue out. Not all have to be that disturbing, but have them at least be brutal. Such as Quan Chi ripping his opponent's leg off, and then going on to beat them with it. That's not as shocking, but it's vicious. More anger and brutality in their fatalities. Have Raiden grab the opponent by their junk and electrify them, only for them to fall on the ground and then have the MK cabinet fall on them. That sounds a bit childish, but the MK team usually likes that kind of potty humor, but IMO it gives a very torturous feel to it. Another example is have Baraka slice off each limb 1 by one, and then cut of the head and put it on his blade and show it to the camera. That's a dick move, but it's a battle to the death, and Baraka is an evil asshole with a lust for blood, it just seems right he'd want to make his opponent suffer more. Make the player feel like these guys really just want to destroy their opponent.

d. Attires:
-I thought the attires in MKvsDC were a step in the right direction. Most of them felt a lot more realistic and dark. They looked a lot less cartoonish/plastic like, and came off gritty. Keep going in that direction and just do everyone's model/attire like that. No more showy or flashy designs, only for alternates if they desire, but everyone should have a serious gritty appearance for at least their main attire. This also means no more sexy unrealistic battle attire for females. MK should be pushing the M rating it's fullest, but not because they want to give the girls skimpy attires with realistic boob physics to give all the nerds somethin to picture during their lonely nights. I'm not saying put a sweater on 'em, I'm saying no more bikinis, bras, thongs, or high heels etc.

2. Better Levels.
a. Too empty:
-The level designs in MKvsDC seemed so empty. I want more destructable stuff within the arena they fight in if it makes sense, such as inside environments, so it seems much more realistic and it's just visually interesting to break through stuff. MK:Deception did a great job in some of it's levels with this stuff such as in Beetle's Lair.

b. Death Traps:
-Stage Fatalities were great, but I just don't see how practical or plausible they would be in a 3D environment, with that being said...I thought death traps were a fun addition to levels, and offered a nice visual both in the background as well as the animation of someone being killed by one. Obviously there were some dumb ones that were silly and didn't fit, but then there were others that were just plain awesome to see. The human grinders in the Beetle Lair was very fun to see your opponent get knocked into, as well as the steam roller one in MK:A's armory. These should come with an option to be turned off, as I understand they aren't for everyone, and another option for them to actually end the match rather than just the round, and they should be harder to be knocked into requiring the victim to actually be closer to the zone than previously, thus making it more rewarding when it happens.

c. Weapons:
-I really enjoyed when the stages had weapons, it was another thing that could completely change the way the battle was played. Of course I am one of those people that can't help but spend half the match trying to manuever my way over to grab the weapon, regardless of the fact that I usually get my ass kicked in the process, but that's all part of the fun. Everyone loves options, and if people don't like the weapons, they should just be able to manually turn off all weapons, or just individual weapons for certain levels.

d. Interactive and Diverse Environments:
-I stated before that I would love to have all those gritty, dark, and disturbing places as level environments, but that doesn't mean every level needs to be that way. I would love for some more diverse levels with some actual interactions between the fighters and the environment itself. A field where there's tall grass that you actually can't see the fighter's bodies from around the waist down(I believe Tekken had a level like this in the dark with moonlight, definitely a stunning visual). How about a level that was previously supposed to be included in I think MK:DA, where the fighter's are fighting in a small shallow pond/swamp of sorts, and from the knee down it's water, and have it be morning with some fog and trees/bushes etc. in the background. Those are just a couple of ideas for interactive levels.

e. Changing Levels:
-I was a HUGE fan of the concept of the Falling Cliffs level from MK:D. I just loved how you had to constantly be aware of the outskirts of the arena, and if you were on the outer parts of the circle you needed to manipulate your way to the other side of your opponent, if not you would fall to your death. More stuff like this where the level can morph and things can change and possible open up more parts of the level, or certain parts become dangerous at times like an avalanche, falling rocks, cars, animals etc. that go through part of the path and can hurt or kill you.

3. Modes/Features:
a. Test Your Might:
-There's really no reason not to have this in the game. It's a classic fun little battle, and now with the likes of online, it would be cool to have this as a pre-battle option for some fun friendly competition, and I am sure the MK team can work some sort of reward or advantage for the winner, if not...simple bragging rights will do.

b. Konquest:
-This is the best way to tell a story, and it really lets you live the story, rather than just reading it. MK:D had a great Konquest mode that not only let you learn more about every MK character, but also let the story unfold right in front of your eyes. It also provided a great mode to gain practice and training, as well as a vessel for many unlockables and secrets to be found and earned.

c. Unlockables:
-It seems like Unlockables have been an after thought the past couple of games. While I know MKvsDC had a few, and MK:A had more, but it seems like they are missing the ball on the replay value it offers. Why give us 50 characters off the bat in MK:A, when you could have made us work for them and unlock them in one by one or in packs? My idea before the game came out was to have them unlocked in sets according to the game they debuted in, starting out with just MK1 characters, and beating it with them unlocks the MKII, so on and so forth. I love having things to work for and earning them always makes me want to play as them or check it out if it's an attire or item etc., but it's as if for the MK team that's not the case. I'd love to see more stuff to be unlocked and earned in the next game.

d. Kreate-A-Fighter:
-This is something that should remain in the game from here on out. It's ana wesome feature that if built upon and polished it could be even better. Add more depth to the customization such as in Wrestling games, and add in more items etc., and you have yourself something that expands your roster and pleases many fans of custom content as well as those who's favorite fighter doesn't make the cut. Though I would like for something like this to be earned through beating the game with each fighter, thus forcing players to still use the fighters in the actual game. Fatalities can either be created from an easy part by part creation system, or you could just go the simple route of having players choose from fatalities already in the game.

e. DLC:
-This is obviously what the MK team plans to do, as they already were going to release Quan Chi and Harley Quinn for MKvsDC before the Midway ordeal. So it doesn't seem to farfetched that we will see some characters and possible alternated released as DLC this time around. Hopefully they keep the price reasonable, about 5 dollars for 2 characters doesn't seem bad. It would be kinda cool for them to take a poll as they did for MKvsDC to see who is high in demand to be put into the game, otherwise I would hope they just put in extra characters that fit in with the story.

4. Characters:
a. Roster Size:
-I would stick with about 22 characters, it seems to be a decent number of people to have, and they all end up feeling more complete and diverse when there isn't so many packed into the game.

b. Alternate Attires:
-If there is only 1 alternate attire, make it really well done and have it make sense. If there is a second costume, have it be classic or have it go along with the timeline/story. Though, if there is 2 alternates, a joke costume isn't too upsetting since you have 2 others to be pleased with. One alternate should be unlocked by beating Arcade with that character, and if there is a second, have it be achieved through Kombo mode or some sort of other accomplishment witht he character such as 25 wins in Versus or Online mode etc.

c. Fatalities:
-I already discussed how I want the fatalities above, but to touch on them a little bit more...Each character should have 2, 1 classic and 1 fresh. If a third fatality be thrown into the mix, a Friendship would be a welcome option, or another classic would be pretty decent. A lot of the old favorites have some really awesome fatalities to choose from. Hara Kiris would be a welcomed addition as well, as I felt they added to the experience and were almost as fun as the fatalities to watch.

d. Weapons:
-These would be nice to have, but I wouldn't be disappointed if they don't include them. If they do however, I would like for the weapons to be drawn by button combination as in your typical special move, like how they did it in MK4.

5. Online
a. Individual Records:
-I would like a record system that also shows how many times you have won/loss against each person. This would be nice when facing friends for bragging rights, as well as against individuals online so you can tell if you seem to just not be as good as a certain person but never remember their gamertag.

b. Tournaments:
-I think tournaments firs MK perfectly, and it would be cool to just set up lobbies, public or private, and have tournaments of 4-16 people. You could also have it set up so that you can watch each match and everyone can talk and have fun with it, or you can just have everyone play their respective match at once and the losers can choose to watch or leave. It would also be nice to have more options for private matches such as time, rounds, fatality time, handicaps, level select etc...just stuff you normally could change in the regular options or cheats on the classic versions.

c. Team Battle
-It would be set up like Endurance mode, where it's 2 on 2, and when one person is beaten the other player comes in. You could have 2 humans vs 2 humans, or you could interchange them with regular A.I. So if you want to just have fun with a buddy, you and him could play against the computer.

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Well those are my desires for MK9 or even the next game. I think this would be my close to perfect MK game, but obviously I don't expect all this for MK9. Though, I would hope to see this stuff in the future.