In an interview with Wassup Conversations, Mikael Säker writer of such games like Battlefield 3,4,1 and The Darkness, talks about a cancelled steampunk open-world game in an alternative history of the 1950s of London. The game was in production at Avalanche Studios, the developer behind Just Cause games but it was cancelled due to economical crisis of the studio at the time. More about the game in the link.

Source: N4G PC Just Cause Developer's Huge Cancelled Open-World Game