I think the way they've lit them is gonna kill a lot of the effect. Look at the Egypt stage. It's dim and red and the ligthing is from the bottom.
Now look at the characters... They're high contrast and lit by white light from above.
See... I always thought that most 2D games avoided really emphasizing things like light direction and high contrast lighting for this exact reason... you'd have to design the characters and stages to conform to some specific rules about lighting and light sources, and it would have to be from directly above, or flipped sprites would be lit from opposite directions... The only stage that would make sense with their ligthing would be a prison yard stage at night or dusk with searchlights following the characters or something like that. I don't see them fitting into any other environment really well, especially not something lit so differently as that Egypt stage...
I'd like to think most people won't notice, but that seems like it would stand out a lot.