this is gorgeous for your first time painting O_O. and an absolutely lovely texture.
this is a pretty different style but i have to say you do it well :D. i love your clouds, although i think the sun could be a bit bigger/more blurred. i think you did a magnificent job with the rocks. and well the gun turned out great XD i would be interested to see an interpretation without the smoke trails but i think they look fine.
awesomeness!