The game is fun, well done. There are some obvious balance issues between characters that has been addressed by several other people so I would just like to touch on something that bugs me:
Just like every MOBA I've ever played the focus in this game is too much on KDA. At lower, more casual levels, where 75%+ of your player base will play, there is far to much focus on Killing and not on the actual objective of the game. The first stat you see after a game is Kills/Deaths/Assists, you reward MVP's (albeit via a vote) based on a single stat shown underneath each character and it's very often Kills or Assists. I've played far to many matches where one player never even picks up the ball or has no interest in actually winning as long as he/she can feel some sense of self accomplishment in their KDA stats. I'm obviously not a pro, I'm likely the definition of mediocrity, but at MY skill level I usually drop these games because similar "weekend warrior" type players aren't pushed well enough into focusing on the objective of the game, instead it often deteriorates into some amalgamation of Call of Duty Team Deathmatch and Super Smash Brothers.