Kick this game off by pressing Play at the bottom of the screen and then the Play button on the right side of the next screen.
You'll see Sonic and his blinking eyes on the left side of the screen. On the right side are all the accessories you can try on him. There are also two accessories in the upper left corner that you don't want to miss.
Simply click the first option you want to try and drag it to Sonic. You can keep it or drag it off and try on something different.
You can also customize your experience by toggling the game's music on and off with the button in the bottom left corner of the screen.
Directions
Select: Left Click