Just get rid of this idea.
you need to take some writing classes. Also, read a few books about writing.
also, create characters that are not recolors.
I can already tell that this is a bad idea rapped up with decent sprite animation with a bit of star power (omahdon) and that is about it.
As Ethernia said before, "nothing to new or interesting"
I found myself forgetting the characters even 10 seconds after I had watched the video. Mostly because I can already tell even by looking at the character descriptions that calling these characters card bored will probably be an insult to the packaging materiel.
So far all the heroes are directly following the stereotypes and cliches. There is nothing new here. Only old stuff that I can already say will be submitted to the portal, raved about because it has Mario and sonic in it. Then forgotten in the hoards of other stuff exactly like it.
Here's what you need to do. You need to forget about this series. Forget about all the plans you had for it. Call it off. Spend your summer doing something original. Take a creative writing class. Do something that doesn't involve Mario or Sonic or some other character or series that has been done to death.
I know you are probably thinking, "but I have some original ideas that would probably be good". Yes you do. But not involving Sonic. You probably could come up with something amazing if you tried. But first you have to grow out of this "Sonic and Mario" stage. Make something original!
Kick this crap to the curb. You've grown up, your a better animator then this. I don't know how many animators on this site that have so much talent, waist their time on stuff like this. You are not going to revolutionize anything or set the world on fire with yet another alternate version of a segaXnintento world. If you look at the movie industry... hell if you look at any creative industry, there are billions of clones when something gets popular, and that's what your creating. A clone, weather it be a clone of dragon ball z, or a clone of sonic, it's a clone. It's copypasta, it's UNORIGINAL.
anyone can do sonic! ANYONE! look at the billion of sonic fan made videos and Mario series around you. do you really want to swim in this sea of mediocrity? and even if your video stands above the rest and you actually achieve something, what then? it's still just a crappy spin on Mario and Sonic. While stuff like Waterlollies and Metropolitan circuit are standing above the rest. Things like Xombie and Mastermind and Tankmen! original stuff that we all compare everyone else's stuff to.
if you created something original it could have the chance to become iconic like these characters. If you created an original story, with a pleasing ascetic and likable characters then you would have accomplished something instead of creating a story of the likes a 12 year old boy could have shat out.
I suppose the TL; DR version of this would be:
Please for the love of god man, don't waist your talents on something so unoriginal and trivial, Newgrounds has enough stuff like this. Make something original! and even if it's crap and you think you could have done better with the idea you had for Mario and Sonic, know that the next idea you execute will be better! and that the path to originality, while being a difficult one, is much more rewarding in the end. You don't see Alvin Earthworm or Johnbro gaining the iconic status of Egoraptor, or TheSwain or Adam Phillips do you?
Also please note that, I am not, I am simply saying you can do better and that this is a horrible idea. the Constructive criticism being me telling you to pursue something original. Also, if you are going to come back with the whole "this is just practice" Bologna, i say Bullshit. You are never going to go anywhere just practicing. If people in the army just practiced and never actually fought the enemies, people would lose all the wars that they were ever involved in.
So, if you actually read this review, I hope my long winded criticism has given you something... lol had to laugh at myself there, you're not going to take this seriously