Looks good...
Two things that throw me off a bit:
1) there are about 6 squares in the grid areas where the shading inside the square is very different to the surrounding square. The most obvious ones are the two squares below the bottom pop bumper. I think the shading in those squares should match the surrounding squares. When they don't, they stick out like a sore thumb to me.
2) I don't like the cartoon flames - especially the big one. Looks a little overdone/forced to me. Not sure if more realistic flames would be better or not, just feels off as it is now.
One thing that I'd like to see added:
1) In the dark areas around the playfield LCD, I think it would be great if there were more shadowed images in the background - something very subtle and hardly noticeable. Just to break-up the black. Probably wouldn't see anything during a game with all the lighting and everything else going on, but would just give that area a bit more depth when the machine is static.
Outside of that, I think the playfield is very good - should look great populated.