It's neat, but it could use more refining.
The Daleks, for example, could instead of being outlined blue, be solid red or brown with an orange or yellow cylyndrical highlight. The form of the green flame is alright, but it seems a little pillow-shaded.
I see a jaggy on all four of the flaming tire tracks- can you spot it too?
Also, I wouldn't mirror the flames. Fire is not symetrical, is it?
Just because I'm picking out a bunch of little errors doesn't mean the piece is bad, or that I'm a better pixel artist. Just my suggestions and comments. Other than that, it's great!
cool guys ) very nice work )