Rocket Fox! Savior of the Galaxy! Defender of freedom!

My goodness, I can't believe that I actually drew this and in full color too.
Inspired by the classic science fiction movie posters of old this is also going to be my final work for art class. It's suppose to be remanisent of the 1930's style of chrome and bronze and sleek aerodynamic designs. Coloring is still a new thing for me so any tips you can give will be much appreciated.

The story: Rocket, a humble inventor living on a back water planet suddenly finds himself thrust into a galactic adventure when rescues a mysterious girl from a crash. Apparently she is the exiled princess of a planet currently under the rule of an evil lord. With Rocket's help she will return to her home planet and take back her rightful place on the throne. Yah, pretty cheesy plot but I love movies like that. It's so cheesy you may just need a lactate pill to see it.