you're a talented artist, but i don't think a t-shirt was the best medium for the design. your illustration is superb although a bit odd (i didn't really know what to think when i saw it). most of the girls are extremely life-like and the coloring/shadowing is extremely well done. keep submitting. perhaps you just need some inspiration from already printed threadless tees?
I truly enjoy the girl tower. For me it tell a unique story about a girl towering out through layers of complex personality to finally come out and breath at the top. The yellow tower looks like a golden statue against the brown background. I also enjoy the artistic stroke in this illustration. I would definitely wear this.