I thought this might be interesting for y'all? I tried to pick progress sketches and concept art that'd be interesting to look at.
We ended up going through quite a few different iterations of both characters and areas to get a better feeling for both my style and how the characters should match their ingame counterparts. Some of these didn't end up getting used or got changed a fair bit in the finals.
When it comes to areas and backgrounds things are a bit more fluid. Not everything needs to or should match 100% as game environments are much more limited by the engine and specs, but they should still be recogniseable to the player.
Let me know if this sort of thing is what you'd like to see more of!
Carl is still my favourite of this whole lot.