Here are some backgrounds for our first game which is obviously placed in prison, so if you could give some hints on how to improve them, that would be great.
(http://i25.tinypic.com/qsw58h.png)
(http://i30.tinypic.com/2054k11.gif)
(http://i31.tinypic.com/rwqgwg.gif)
There are some obvious perspective flaws in your backgrounds but overall to me they're really nicely drawn and the angles are nice too. You've thought about shading which is good! The only thing that really bugs me is the path in the last shot, and the size of the bricks nearer the back of the image. I'm sure someone arty can give you a few pointers :) None the less good job!!
The cell looks quite good, I'd probably leave it as it is for now. It's in perspective, and the shading looks quite nice in it.
For the second one, I'd perhaps add a bit more details into the bars - many, many bars! Perhaps if you make them slightly thicker on the closer ones and the bannister (by about one pixel), but make it darker below or away from the light source.
For the third one, I'd have a look at the perspective. It looks like the lines aren't converging towards a common vanishing point. Also, I'd add in a bit more "noise" to the path and the grass, to make them seem a bit less flat. Maybe little clumps of dead grass here and there, since it's a prison? (not widely renowned for their horticultural prowess)
Other than that, it look like a good start. As I say, the cell is my favourite thus far.
First image is really beautifful. Maybe could be good if you will replace grey on walls with white.
Quite often prisons don't have white and grey walls. Alcatraz, for example has a green tint to everything. It's not mould, it's thanks to Psychology.
Green is used as it affects mood. It's more likely to make the prisoners more passive and to stop them going crazy.
Insane asylums and hospitals use the same theory when decorating.