Not bad for two colours, the score and time are a bit hard to read though and I think you should have stuck with the angled style the whole way through as the mushroom, clouds and hilltop kind of break what would be a consistent style.
Very interesting style., but it seems a bit plain. Which was probably your aim. I like the Koopa. :)
At first my clouds were angled, then I wanted to do them (and mushroom) more 'mario classic'. Perhaps I was wrong. Thanks for feedback, guys!