Vikings out of context ftw.
Your houses look like they need some help with perspective, or generally showing their angle. Right now thay look a little flat. Quick test:
Of course that adds another colour, but using the current palette looked a little odd:
Tested making the trees darker as well. Also noticed that the gap on the top of the house is not dead centre. This could be because of tiling, but shouldn't be hard to fix, unless you ment it to be that way. I would also suggest experimenting with some sort of outline on the wings. I feel they don't match the rest of the character too well, but more importantly, they could get hard to see with shifting backgrounds.
That said, I like they way this is turning out. I'm getting some serious deijavou from those cactuses. Looks exactly like the ones I designed for a commertial a short while ago.