Okay start. A little background music could spice up the game. At one point the game ended suddenly when I did not appear to crash into an enemy. Is it possible for them to spawn where you are sitting or is there a hidden time limit or coin count that ends the game?
P.S. How did you get full screen to work properly? If I use the default settings, it just expands the screen to the right as opposed to increasing the size of the game content along with the window. I thought I found a way by tweaking the settings, but turns out it's glitchy.