I saw this and thought WOW
.I think the mini map view is quite beautiful and I can tell you spent loads of time on it, lots of attention to detail.
I would suggest taking the lava wall out of the middle though, with it the game becomes simply a race to the middle cities highly favoring the player who goes first.(or builds elementals) I would bet 95 % of victories on this map will boil down to who holds the middle. I do see that you added the side passes to add another option to break a standoff but it is quite out of the way with tough terrain, I'm afraid launching any successful backdoor offensive would be almost impossible.(skills being equal) You could add a few more passes (without a city -refering to group ambush issue) through the lava to give a few more options, but I believe the game-play would be more enjoyable without the wall altogether as your map has plenty to offer without it with it's balanced varied terrains, rivers, ports, and bridges.