I think...the only thing i really like about the wall is composition and perspective. the modeling is decent, but what upsets me greatly is the ack of lighting and lack of textures. i'd imagine you were going for that cartoony look, but it's not really there. and if you were going for realistic, it's not there either.
i dunno what program you were using, but if it was 3dsmax or maya, i know all you'd need to do is play with the hypershade and throw in some lights with raytracing and the wall would be a thousand times better with just an extra 15 minutes of work. if you used bryce, well, i know bryce's capabilities are way more shallow than a program like maya, but i havn't used it myself. even so, i'd imagine it's lighting capabilities are enough to at least enhance this image.
overall, i find it's kind of plain. the lack of lighting is a shame, because in 3-d, lighting is half the project (i had a 10 week project, and i modeled for 3 weeks, lighted for 6, and tweaked for 1). It's a nice concept, and composition is great, but the technical aspect is lacking. and unlike ish, i prefer the sense of depth. so you get a cookie for that :3