I rarely say something like this: I think I'd like it better if it was a tad smaller on the shirt. I don't know, I just really like the overall shape. A minor detail that won't stop me from loving it: $5
I like the placement of it. The illustration says very "Step into my Reality" as well as "Step into my Universe" because the Earth and the Stars are details in a much different style than the girl and the borders. My only other comments are that her left leg looks longer than her right, which looks slightly funky, and her left shoulder/arm is coming out from her hair a bit too much perhaps, giving her more broad shoulders versus a slightly more slender look, if you've got any issue with that.
About my design