... not a proper review, for which I apologise, instead, here's some tips and where you can improve things. Firstly, the voices, please re-record the voices and dramatically improve the recording quality, Link and Mario's voices are grating and extremely unpleasant. Look up some voice acting tutorials for recording, for example RicePirate's 'VO Home Studio: Space'.
http://www.newgrounds.com/portal/view/590285
Please have a look at some recording tutorials, and NOT just the one above.
Secondly, please try to improve your script. This animation provides nothing new, that hasn't been seen before in many, many places. Yes, Toad looks like a mushroom and yes mushrooms are a power-up; this observation has been done many, many, MANY times before, so it provides no humour. Same with Mario being 'addicted to mushrooms' or Sonic being fast. And PLEASE don't use canned laughter like that, it's utterly incomprehensible, unless it's a very poor attempt at 'ironic humour'.
The one attempt at originality that I could see here was Toad's 'speech', but that was very poorly executed and I couldn't tell whether it was supposed to be funny or clever or what.
Thirdly, the animation is a bit weak, needs more work, especially if you're going to use some FPF stuff (such as the cape) which need a lot more frames to look half-decent. But, even more so, the quality of the drawings varies a lot, some horrible (Mario's face looked terrible in the 'shrooms' part), some ok (hopefully you didn't simply trace them). Go for more consistency in the way characters look and try looking up some drawing tutorials.
And don't just randomly incorporate a 'Oney face' like you do; it's not funny, it's not original and it just looks bad; especially since you don't seem to understand how to use it effectively.
Finally, fix the aspect ratio, it's clearly wrong and we can see the 'white space' above and below that we aren't supposed to see.
Having said all that, I don't want to discourage you, not at all. This is an impressive animation for someone who's clearly starting out and you show both promise and ambition; the simple fact that you tried to do some FPF and it turned out merely poor, as opposed to downright bad, is a good sign.
You also tried to vary the camera angles, including some dynamic stuff, tried to incorporate some original elements, it's all much more than I'd expect from a a clear begginer, so kudos on that, and I hope to see some truly good animations in the future.
Above all, practice, practice, practice.