aint bad
But still a few things you might wanna keep in mind for your next animation: don't overdo it with the blurr effect, for example: at the beginning when mario was in the back and sonic closer in front, you switched focus by adding a blur to the one not focused on and showed the one focused on without that blur. The idea was good but you only need to add just a tiny bit of that blur to get the right effect.
The last thing: gravity, what do i mean with that? Well, when a character jumps, you use a motion tween to do that. Now that's not a bad thing but you should keep in mind that in the begining of the jump, the character goes up really fast and quickly slows down, then when he falls down his speed increases. You can do that by going to the timeline, klick on a frame between the two keyframes of the motion tween, go to properties and add a number at 'ease'. A positive number when he's going up and a negative number when he's going down. And if that doesn't work for ya, you might do it frame by frame.