I know that this is unfinished art, but are the lines staying as thin as they are now? It seems a little thin to me for the size of the picture. Perhaps it won't be so apparent if you add colour (depending on the style of colouring), I don't know.
Anyway, I think this is a good start after a long break. It would be interesting to see your finished version of this.
It's not a bad job, per se, but my advice would be to practice at varying your line thickness. It'd add a lot of depth to the picture which looks a touch flat my comparison.
The expression should appeal to the "tickled to madness" crowd, though.