I got way into Prosperous Universe for a few months, a few years back—it was fun for awhile but the pace at which new features were being added to the game was (and still seems to be) absolutely glacial, given what the game is. Really fun ideas in there, though.
replyThere's been some new features in the past few years. But you're right that the general pace of new features is slow. There's only about 0.8 developers working on the game.
replyHowever, if you're the type of person that likes to work on spreadsheets to calculate profit margins and market trends, Prosperous Universe is worth checking out.