Not good, but could be with improvement
Starting with the cons first:
-When you hit an anvil and can't go on, you have to fall back all the way down. It's annoying when you fall down and hit a star that brings you up. All that does is waste time.
-Beating the game left me with a "Wow I really wasted my time feeling" greater than most upgrade games tend to give off.
-Stuff like the bird and the whale that don't affect you are graphically placed so they look like they would do something if touched, so I was dodging them the whole time. I would increase the contrast to make it look like it's in the background, or just not put it there at all.
-The fuel wasn't very useful. It should have given off a much larger boost since a quarter of the game's upgrades regard it.
Here are some pros:
-For the most part the graphics are well drawn
-The boxes that shoot you up make the game more interesting, but I thought they acted like anvils at first
And last I would like to suggest a shorter logo that represents whatever site you're promoting. They look very nice, but people playing an upgrade game are likely not fond of a full minute logo sequence. Also, the music is nice but it gets pretty annoying as it is the only song played throughout the entire game.