I really like the third one (the scene on the Moon) [Is the idea yours? It looks unlike your other works.], although it has lots of things to work on. Firstly, I don`t like the edging of the flag. I usually use the same colours as the ones near the edge, but a but darker (how much, depends on the brighness of the surface it touches). Then, the shadows are different (the ground under UFO says that the light source is on the right, the ground under the astronaut says it`s above), moreover, the flag has no shadows at all. I also like the minimalism, but your picture seems to lack something. At least don`t draw stars in one pixel - try to use "+"-form with the brightest pixel in the midle of four a bit darker ones. And try to add something - may be it will get the picture better. May be not. I don`t know.
I let others to say something about all the other pictures, because, as you can see, if I write about each one, my text post will be as big as yours with pictures.
The only thing I want to ask: is that just a specific style in the first picture?
