I've also made a shoot'em up game last year december in a day or 2 to celebrate the silliness of Doge Coin.
I did make use of the moving background to increase the sensation of speed when speed power up is taken( Eventhough i know the background should not be moving at all :P)
This is pretty good. But does the free account last forever? Last time i was lured into signing up upcloud.com and was forced to pay a month later or my entire account gets wiped out.