CONGRATULATIONS, you have been selected for my first critique! Ha but anyways, here's my two cents.
It's detailed and colorful. I think overall, the impact this piece has on the viewer is all very well. The poses COULD be more dynamic, but I think for the style and composition, it looks good. The shading is very distinct, you can easily identify the dimensions of the characters. The only advice I have on the shading, is maybe there could have been a little drop shadow under the little baby dood.
I also feel like the colors were a little rushed, it seems like there's a lot of spots where the color goes out of the lines, or doesn't go to the line all the way, etc. The background could have also benefited from being brighter I think. The grey background against the grey characters muddies things a tad.
The only reason "originality" is so low is because this is fan-art. You're not really seeking out to do something original anyways. xD You just wanted to draw some cute pokemon.
Really though, fun piece. I hope to see more