The two games that I have finished (in one go) have lasted 13 and 15 hours respectively. I have played 4 others in an ongoing format where we would play a turn every other day. All of these games lasted over a week.
Japan is ridiculously strong (but then is on 1940 too).
Germany can be held a while and Italy should not grow at all, but the U.S. must invest nearly all its income in the Pacific.
Still makes a refreshing change from 1940 though.