Combat occurs only after both players have moved - not after each side's movement. The first player in a turn can attempt to pin enemy units during his movement phase. You may move through an opponent's naval force provided you leave at least as many units in that hex as he has there. A victorious attacker can reorganize his units among the spaces he came from and the space he captured - a rule that should be ported to Victory . The only ground units are marines, infantry, and garrisons.
Submarines have some advantages over their Victory counterparts, largely to do with supply.
At this point I find it one of the best block games - very balanced and tense, though I think the Japanese can't really win unless they have either great luck or an inexperienced opponent. Still, it's great fun to play - time will tell if it still holds up to that promise. Actually, the game requires an interesting collection of both offensive and defensive skills in order to win. The Japanese player must be very good at offense early in the game, and very good at defense later in the game to have a chance at winning. The Allied player must be skilled at both, but in reverse order.