The part in the video with Fox going all apeshit on Goku really puts me off. Theres an insane amount of combo chaining thats very unnatural to the whole Super Smash feel/theme. Super Smash is a game where if your damage is 100% or more, you fly a decent distance when hit with most types of attack. So seeing Fox chain multiple attacks with several very distinct moves really turns me off. If I wanted attack combos of that calibur, I'd look towards traditional fighters. To me, Super Smash-type gameplay isn't the type of gameplay to exploit a constaant flurry of repeat moves until they're at death%. And if you insist on keeping comboing like that, then I would just even conside some sort of combo-attack break system to keep opponents from being spanked. Because it seems to me from the videos that once you begin the combo, you can keep getting cheap hits in with the opponent not being able to do anything except just take it.
Other Super Smash games never needed a cap/break system like that because insane comboing like in the video weren't ever possible after 40% damage. Of course is a fan game and it is your game, but just saying that after a quick 3 minute observation of insane-combo frenzy, it looks less of the Super Smash title you're trying to emulate.
Though I will go on to say that it is the best looking Smash clone I've seen to date... I mean its only like the 4th one, but still the best.