Sonic Smash Brothers BETA is an action packed fighting game, similar to the Super Smash Brothers games, except this flash game only features playable sonic the hedgehog characters. You start off in Adventure Mode with three playable characters... Sonic, Knuckles and Tails. As you complete adventure mode with each of those characters, you unlock other characters... Amy, Rouge, Shadow and Cream. You can also unlock more characters through various challenges as you advance through the game. This game is a must play for all Sonic fans!