it needs more contrast.  try choosing a more dark color for the shadow and balloons. and a lighter color for the highlights.  i'm still new at pixeling too so... my advice may not be the best there is :P

i think u shud change the shape of the guy to look slightly less gay but otherwise its quite gud

Don't jump the gun with stuff like antialiasing yet: you need a grounder in the basics of shading, composition, and color before you delve too fully into a specific medium, such as pixel art. I recommend you seek instruction in the form of an art fundamentals class at your place of education or look for a primer on the web if that isn't an option. You'll be surprised how much you improve with a little formal education as opposed to a boatload of critiques; a forum such as this is suited to tweaks and opinions rather than instruction of the groundwork those tweaks and opinions are constructed upon.