Nice use of colors and shadows!
About a critique... I think the silhueted characters are too small for their normal size... Mainly the girl, that seems like a doll in this scale. The Big Sister, that is huge in normal size, seems like a normal human in this scale.
I think the hands in first view should had worked more detailed, considering that is in a 1st plan... Mainly the right hand.
Building's perspective are a bit strange too. The perspective line of them don't match with the perspective lines of the windows.
Anyway, to be honest, just the first critique really count. The rest was just because DA need a mininum of 100 words, hehe. Nice piece anyway. Congratz.