Asylum of the Daleks

I do like the composition and the use of colour and line work. Reminds me of old movie posters. The likenesses of the characters aren't too strong, not that it is easy to capture Oswin or Rory and Amy. The Doctor's face is pretty much there, although he does seem to be somewhat flattened. Might be better to go for a profile view of Matt Smith as he does have a very angular face.

The Daleks are definitely the most well rendered of the characters, which goes for the Dalek mutant as well.

I like the way that you have used red as a motif within this picture, reflecting Oswin's red dress no doubt. The overall effect is almost two toned, apart from the Doctor's jacket which remains close to its original brown.

The choice of font for the lettering is interesting, if somewhat unconventional. (I'd expect to see the Doctor Who logo and maybe those squared off Dalek fonts from the comic strip).

I would see this very much as a work in progress, like a mock up of a final picture.
Good work and strong composition.