SCN, this looks really promising. I got some suggestions
-Some places are too empty, like that island on the bottom right. Best place some buildings and creeps there, as well as some trees, perhaps cliffs or some water... It just looks too open in comparsion with the top right path.
-The bottom gold mine is near the water, which means it will be attackable by boats, whereas the top one is not.
-The blue player's starting position is too small, expand it to the north like the red's.
-Too much open ocean. A few unreachable islands around that center one, some sunken ruins in the water or corals sticking out, maybe even some islands with fountains of mana and some turtles?
-Best keep it to boats only, zeppelins will make boats useless. Thus what's better than attacking your opponent's base with hundreds of boats full with army?

-I like the unsimethricy of the map, but at some places it's just too... radical. For example, the middle right gold mine and the 2 green camps are too much to the north, which makes it unfair for the blue player, as he has to travel more to get there.
-Best remove the walls from the gold mine island in the center and make it just an island with a few fortifications, but open to the ocean. I mean, it's the only red camp in the map, it should be hard to take over, and most of all, hard to hold your ground there. With one enterance it's quite cheap. Also you could scatter some ruins in the water around so the attacking army will have trouble getting there by boat

-Middle-right island looks boring and empty. It's all sand with a rock in the middle... As i said, some parts of the map are too empty.
-You could make it an altered melee, by adding personal buildable shipyards to every race with battleships. That would bring back the good 'ol WC2 feeling :3
(speaking of WC2, your scetch really reminds me of the WC2 wasteland tileset

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Looking forward to your map

(btw sorry for the bigass post

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