The graphic style is inconsistent. Especially the river. It looks weird.
The gameplay is ok.
The yellow and red thingie doesn't look like something good. I couldn't tell that it brings you coin until I actually try to collect them.
The jump animation isn't obvious enough. I couldn't easily tell whether I'm jumping or not.
The game is quite buggy. I can't get out after clicking on the button "control" in the menu. And the post-game exit button does nothing. I expected it to bring me back to the menu. I bet that the button closes the game in PC version, right? If so, you should make two version of the game. One for PC that has an exit button, another for flash that has no exit button.
Overall, the game is not bad, nor good. It's ok-ish.