Hello! Created an account just to give my regards on how awesome this map is.
This map is very unique. It's very simple gameplay, but each elemental force has it's own special twists in resource gathering, unit set-up, and gameplay style.
Fire: This is my favorite, second only to Nature. It's quick, aggressive, and gets the job done. You gather resources on the go, even while you attack the enemy. Fits the element well.
Light/Darkness: These don't seem to fit in with the melee/capture and hold style of the map, in my opinion. I guess I feel that this element's forces should have a tie in with how much of the map is revealed. Maybe they get stronger in the day, the same as Darkness does at night. Darkness' units work well enough for a hit & run/stealth sort. The Dark Shrouds need to be unselectable though, please.
Water: This element is good to tie in with Fire or Wind, as it does have the most flexibility. Pretty much the most well-rounded of them all, and it has the best resource structure in my opinion. Very good for massing tactics.
Wind: It took a bit for me to get good at gaining resources with Wind, but after a bit, I had it down. Their forces are very aggressive as Fire's, and three times as maneuverable. A very great harassment element, especially if coupled with Light or Darkness.
Nature: This one is my favorite. It seems to be what Earth should be: A turtleing, powerful tide of strong units. It's one of those elements that you know what's coming, and you know you're screwed. This pretty much goes well with anything.
Earth: I haven't had a lot of experience with Earth, but they do seem quite powerful. Their spellcaster unit is awesome, and the grunts are good, but it seems like Earth should be more of a base-building, elements that becomes really strong later in game.
Plus their resource gathering kind of bugs me.
All in all, I really love this map. It's the only one of it's kind that actually does the whole "Elemental Warfare" thing well, and I hope you continue working on it, at least enough to get the elemental fusion system up and running.
I can't play it on Battle.Net, but it's a favorite among LAN parties.
EDIT: NECRO POST!
(Hope to see your map-making skills in SC2)