Hello, I finally signed up after lurking for a while around here just because I love this piece so much. I hope its not too late to give my tips for it (eg its gone to press already).

I wrote a big block of text about making sure you have a bleed on the art but on closer inspection it looks like you already have included one. So my other advice was to make sure once you're done to scale it up to 300 dpi yourself. You don't want some noob pre-press guy doing it for you and using bicubic instead of nearest neighbour.
I think having the pixels any larger as was suggested would make it more obvious if the trimming is slightly off, as it isn't very precise in terms of cutting between 2 pixels or even straight for that matter.

I think the street lights need a little tweaking, at the moment they look like they are pointing onto the footpath, not the road. Either shading or the angle they are on is causing that, not sure.

I wasn't sure about Ixis' comment about making the leaflet seamless, I liked the idea of having some of it contunue and some not. Then then I realised you could just make the building in the 'space' side futuristic versions of the current ones (I assume they are the buildings on the flying chunk of rock in the background of the other picture). This way they could flow on from the other buildings but still fit in with the space area. Not too sure how this would fit in with the story you are telling though, as in, it would mean the monster is attacking the flying city not earth.

Who's Sam?