Background looks fantastic, but the character integration really irks me.
Here's a quick rough try (probably went a bit too far):
edit:

-- Space, to compensate a bit for the objectivity distortion comparisons causes.
original:

It makes the colours of the guy in particular very bland, but that could be fixed. Also reduced the contrast in the talk bubble, as it stood out a bit much as well in my taste.
The photoshop file - just added two adjustment layers (~500kb (ps cs3)
Haven't tried the game yet, but looking forward to it!
Edit: added a bit of space
Here's a quick rough try (probably went a bit too far):
edit:

-- Space, to compensate a bit for the objectivity distortion comparisons causes.
original:

It makes the colours of the guy in particular very bland, but that could be fixed. Also reduced the contrast in the talk bubble, as it stood out a bit much as well in my taste.
The photoshop file - just added two adjustment layers (~500kb (ps cs3)
Haven't tried the game yet, but looking forward to it!
Edit: added a bit of space