Nice colour palette. Brown in reddish brown with greenish brown and yellowish brown. 
Ok, that may be because its a swamp map, but still.
Imo there is an overabundance of earth tones in Elemental, and it makes the game look kinda bland. Also, you should take a look at lighting in battles. The current light source seems to be a bit too high, so that units always look very dark.
It's very apparent since I've just played some King's bounty. There we have all colours, like, blue, greenish green, yellow yellow, etc. 
Ofc part of why Elemental is a bit brownish lies in its art direction.
But can we have some more vibrant colours? (No. bloom isn't vibrant, bloom causes eye cancer.
)
On a positive note though, the artwork looks great as usual. You've really nice art direction in that part, very distinct style. It just doesn't copy that well over to the game yet. Especially the landscape. :/