It's a shame I'm too late, but I'll give my ideas on what I invision as the perfect platfighter anyways.
8 button, fighter platformer (I mean real platforming, hard to get to areas.) Timing, and very context sensitive. Weapons are character specific, and appear on the field as icons (e.g. A sword icon falls on the field, and Quote picks it up... you get Kings sword! It would also be cool if there was a battle log, and each game would have it's own text style, so Psychosomnium gets that annoying t/y letters.). In the area of timing, an example would be that depending on how long you hold your direction/running will change attack.
Another idea I have would be traps, which is the reason for the 8 buttons. Traps would land on the field as items (both original and from different games) and could be placed on the field along with a trigger for the trap, in the form of an arcade button. When these [the buttons] or the corresponding key to your trap (e.g. Q is one, W is another, E, and then R) are pressed the trap sets off. This allows for a higher level of strategy.
A-Acrobatics: For jumping, rolling, climbing, maybe dodging.
Left/Right+A=Jump that direction.
Down+Left/Right+A=Roll that direction.
Up+A=Extra Acrobatics, character specific.
Close Up+Left/Right+A=Directional Extra Acrobatics.
S-Attack: Basic attacks. Specific for each character.
S= Most basic attack. Usually in the form of up to a 3 hit combo.
Left/Right+S= A more forceful hit, moves character slightly. Good to end combos with.
Down+S= When on ground is usually a trip, and in the air is usually a dive downwards.
Down+Left/Right+S= A downwards diagnal attack, might be a dash kick (Like Megaman). In the air diagnal downwards kick or dive/slowly descending kick.
Up+S= Attacks upwards, on ground maybe an uppercut for most. When used in air it might stall your fall/send you higher slightly, while attack upwards, plummeting faster.
Up+Left/Right+S= An upwards diagnal attack, in the air might be a spinning attack for a lot. On ground sends you in a small arc.
D-Force Attack: Special attacks, more specific for each character. Often longer ranged than Basic Attack. Weapons would effect this and the grapple buttons the most, and at the start of each round you get to equip a different weapon for each character. Weapons include None, Sword, Gun, Bow, Axe, Special1, Special2, Misc., and Joke. These could often be used for different effects than just attacking, with unconventional controls, but still directional and position sensitive. Completely character/weapon specific.
F-Grapple: Grabs/Special character specific actions (Can be effected by weapons, but not usually very much.) Directions and Positioning can completely change attack, instead of just direction of attack. Say you grab the enemy from the back pressing away from the enemy+F could be a supplex, forward+F could put them into a hold, down+F could stomp them down, and up+F could break their neck. Then the diagnals would be different as well. Grapple could also be used as a block/counter.
Space-Interact Button: Context sensitive. Can be used to pull a switch, or a special interaction, for example, if the enemy is on the ground and you press space you could spit on him. Many different interactions, like sticking to a wall, or kicking off one. Can be directional, but rarely. It would show on part of the screen what the possible interactions are, and what the directionals would be. When you grab someone it would also show the options.
Notes On Gameplay:
HUD/Screen Layout: The screen resolution would be set larger than the actual gameplay, like a frame only not showy. All of the information would be shown there, and it would be exactly 4 times larger than what you see. This is a system that allows for zooming, and panning. The area would be designed to fit into the view, but would not be shown like that unless A) the player sets that option, or B) The characters are far enough away. The HUD shows, a percentage system like in SSB and a Health System. The percentage indicates how far you will go flying, and the health indicates HP. The screen would also show your interaction options, what song is playing (The game would have remixed versions of the songs from other games.), your items/equipment, and the traps you have set. There would also be a bar which shows the tug of war of battle, (When you hit an enemy it goes towards you, and vice versa.) different attacks would be balanced to move it more or less, and killing the enemy would move it even further. This would be one on one, but (unless someone figures out how to do the bar thing for more fighters) the game could be played in time mode or with lives for up to four (not on one keyboard, sadly.)
Weapons, again: Remember how there where multiple weapon types, they each do something different. Each weapon has a different basic use, even though it's different for each character. Your weapons could be beaten out of you, and you could probably throw them away.
None Equiped: Makes your Force Attacks, stronger but slower versions of your Basic Attacks.
Sword Icon: A stabbing/fast-but-weak, attack type.
Gun Icon: A straightfoward shooting pattern/fast-but-weak long range attack type.
Bow Icon: A special (out of the ordinary) shooting pattern/slow-but-strong/charge shooting long ranged attack type.
Axe Icon: A swinging/slow-but-strong attack type.
Smiling Face Icon: Often different from everything else like a more complicated special attack type, usually something that can be used for extra purposes
Star Icon: Similar to the above, but it often comes as a special form.
Exclamation Mark Icon: A joke attack, something that is very stupid like a joke from the characters game.
Other Icons: Misc. attacks/forms. For Quote one of them might be the Jetpack, little stuff.
Traps: The traps are used like I explained them above. They don't come in icons, and are sometimes generic or just from other games. They can range from bombs, to trampolines, or even enemies from a specific series.
Modes of play: There would probably be many modes of play. Below they are listed.
Basic: A two player tug of war.
Lives: A battle of lives with up to four players.
Time Attack: Score the most points you can in x minutes.
Context Mode: Play the game with the arrow keys and the Interact Button. Up to four players on one keyboard.
Victory Mode: Get enough victory points to win. (Like the GBA Digimon fighting games)
Adventure Mode: An adventure mode like SSB Melee.
Smash Mode: A mode of play that gets rid HP, only using the hit percentage.
Story Mode (Tentative Title): A crazy crossover story like Subspace Emmisary.
Platform Mode: A mode comprised of only platforming levels. Co-op play, where the second player plays as defeated bosses.
Comboing: Combos would not be preset. Instead they would be huge branching systems, where the player must find which combos work for which character/which weapon and you can press the interact button at the end for something like a special/flashy finish. I also like the idea that every character has a weapon level system that would be series specific.
Final Notes: Instead of making just one build and only fixing bugs, you should often add characters, and update characters. Because of how long it would take to make a character the roster could start off limited and then expand. I think that's about it, and the updates can keep a good comunity with character polls and everything.