You've got a good style going for the character in this one. Sort of reminds me of the large french comics with the way you've presented it.
That said, there are a few things that could need some work. The ears and position of the legs have bothered me a bit. I like the palette you've been going for, but you don't seem to be using it to it's full extent. Here's what I mean:
The rock he's standing on has more or less open areas with tiny shaded parts on them rather than giving it full volume. With so many colours, you don't necessarily need dithering to the extent you've used. I managed to shade the rock and grass using no dithering at all. I replaced the brightest rock colour with a brighter, less saturated one, because the two brightest ones were nearly identical with one just being in a yellow hue. I also removed one of your grass colours that was too similar to another.
Since he's a space dog, I put a planet in behind him to help with the theme. I also made use of all your sky colours that you had spread out across very small surfaces to unify it better.
For the dog, I fixed how the ears connect a bit, and moved the legs to get him back in balance. (he was tilting towards the right.) With the dark shadow he's casting on the grass, it would only be natural if he had the same amount. I increased the contrast and lowered the saturation to mimic the rest of the picture. Lighting up the outline facing the light was not necessary, but it shows an alternative way to do it. Also added another arm and was on a roll so I added a tail for good measure (him being a dog and all.)
That's about it. Hope I could help out.
