Avoid obstacles by pressing the up arrow key, space button, or tapping on the character. You can change the character by tapping on it on the start screen. There are fun awards* to earn at different point levels and stuff like that. These will allow you to unlock several other characters.
*The "Halloween Hero" achievement is not impossible.* July 11th V 1.0 ---> Game finished with high scores. August 1st V 1.1 ---> 9 awards and award screen added. August 2nd V 1.2 ---> Reward Characters added for getting awards. May 11th V 1.3 ---> Released again with cloud variables.