Hey Adrian! Since you're asking for criticism I'm going to help you.
Well, I really like the concept of "Frustrated Artist" XD. I think we've all been through that troublesome time when inspiration is missing. I have to admit that I've made that Fella's expression more than once!
Also, I loved the colours you gave to Fella in the first desing. It's too sad you can only use 6 solid colours but, however, it still looks very cool!
I think I wouldn't change anything. The colours suits to this t-shirt very well, and the font is something that goes verey well with the "frustrated" concep. Yeah, I think this is something I'd definetelly buy!
So, good luck with the contest! ^^