I just noticed your comment that your target audience will actually be teenagers, so I have made a couple of changes using the similar idea (person reaching for the stars). I have made the figure more grown-up and altered the text to look bold and edgier. Overall the new designs stay away from whimsical and childish.
Thank you very much. We showed the designs to our Board and all agreed they looked too young. Do you think we can work together to fine tune some a little?