I can finally reveal that I was involved in some concept artwork for the game Sonic & All-Stars Transformed, the sequel to Sonic & SEGA All-Stars Racing. The idea was to have hundreds of SEGA-themed stickers available in order to customise your in-game licence.
Sadly for a number of reasons, these stickers (along with more coming shortly) were not used for the final game As much as I was (and am) disappointed that they weren't, it was a fantastic opportunity to have on top of my regular responsibilities during my time at Sumo Digital Studios. Getting to draw Sonic artwork in an official capacity? Hell yes! Hundreds said I would never get to, after all. So I'm halfway there!
...That isn't to say that these couldn't become actual stickers in future... Stay tuned.
EDIT [21.11.2012]: Placing an edit here for both deviations, as it seems that some people don't understand the term "concept" i.e. They were not the final product, and would have gone under approval so that amendments can be made. I also had to whack out twenty concepts in little under a week, so of course there are some of them that look a little off!