IMHO the problem with MoO ]|[ (yeah that's the official logo) was not that it was too complicated, not even that it was too hard. It was just grossly unfinished, with half the planned content missing (mostly related to how society and leaders work - it was supposed to be a hardcore simulation). What we got was a messy random mass of features and, even worse, it mostly played itself - the player had little to do, unless they wanted to micromanage everything that was very tedious and not all that rewarding. Add horrible combat (again, fully automatic - no decisions were making any difference) and ugly design (not just aliens races, everything), and here you go.