Lol! :D                   

It's a good piece, I have to agree with susuwataris about the speech balloons. They pop out with much force. If there was no speech balloons but still have the text (a bit lighter, though), then I'd think It'd look better overall with the piece.

I like the left side too, too bad there isn't more of it...

I love the idea of the city behind the rock, but the speach balloons are kinda bothering me, also the font is uncomfortable to read.