I wonder how you'll handle this. Because if you'll e.g. have two difference highscore tables for DRM-free and Steam, there will probably be a lot more activity on the Steam ones. Or will there be one for all versions? (Or - one per platform. I guess one for ALL really wouldn't make sense considering the mobile versions)
The plan is to store all the high scores from all versions on our servers. Exactly how we will filter those scores for display has yet to be finalised.
With so many developers relying on the Steam servers and not offering any online leaderboards for their DRM-free versions, I was quite worried about that.