I love the way the chains really stand out in the picture, and you can feel the pieces breaking. Just by looking at em, you can tell the type of damage that is being done... really amazing.
I think the empty sky helps add to the sense of scale, and the repeated top part of the building is more realistic. That's how buildings are constructed.
On the other hand i don't really get a sense of scale or perspective from the huge chains disappearing into nothing.
The chains at the base, in the forest, appear around the size of a small building, and i can see small buildings in the city, ergo i should be seeing the chains attached to the tower.
I think it would help if you replaced the dark shades on the tower with light shades, so it's fading off similar to the hills in the background.
edit: I made a really fast edit to demonstate what i mean.
http://i58.tinypic.com/9hkh3c.png
you need to lose shadow and detail the further back something is, so the tower shouldn't share the same detail as the chains in the FG.
You are quickly becoming one of my favorite artists on this site!
the concept
also as mention before, some perspective issues and of course lighting, someone threw the word "pillowshading" in the room, and indeed, the complete piece feels like its pillowshaded, it has no real depth for orientation that leads through the piece
you should work on smaller pieces like 1/3 of the size OR plan out the compositions prior pixeling
A very cool concept, well pixelled, nice design, but... What's going on with the perspective here? If you compare the chains to the nearby trees, it looks like they're connected to something many, many kilometers away. But the colours of the chains don't fade into the distance, and the tower is the exact same saturation and contrast as the closest links of the chains, as if they were all at an equal distance from the viewer. And the size of the trees surrounding the tower completely go against the illusion of distance created by the chains. Maybe this lack of realism was intended for some abstract effect, in which case it's all way over my head.
Whoa... this is awesome... wow...
EDIT: after picking this apart I couldn't help but notice isn't the tower pillowshaded?
not only chains are broken here...