OCC is stripped-down Civ2. You need a really good starting location, you need a tech plan and a build plan, you need to focus on key wonders and improvements for research and ignore temptations to war and explore, you need to swallow pride and be a pacifist in order to milk AIs for gold and tech (early on, before your research machine gets going), then keep them happy with just-in-time tech gifts especially to your KeyCiv. You need to focus on trade, both early trade routes and keeping one or two commodities unblocked in the mid/late game for repeating deliveries, while using surplus gold to rushbuild food caravans to stockpile to assist building your spaceship. You need MarcoPolo or embassies with as many civs as possible in order to watch what they are working on and milk alliances. OCC is not a build-everything game; it is a tech-dash. Several players have done OCC in recent GOTMs; check the Spoiler threads to see if anyone posted a log. I'm on vacation at the moment but #43 or #44 might be a good challenge for OCC.