Given the limitations of the tools of MS Paint, it's actually very good. If you had something with some real meat in it, you could probably take your concept a few stages further and be the envy of your group of friends.

The 'I just did a picture but OMG it sucks and I'm the worst artist ever' thing is so absurdly common it's clichè. Go ahead and enter it-what have you got to lose? I think with how colorful it is it evokes New Years, even Mardi Gras (choice of colors) than Happy Hour, but that's just my opinion as an art major.