Always watch for the Red's big spheres, sometimes they will expend a lot to get a small neutral one, remember a weak big sphere > fed small sphere in the long run
This game is great except for one thing: Aerial units. Why is there only 1 unit that can hit flying targets and 3 melee units? In the end, once I unlocked torr I never used the knight and when I unlocked knight I never used warrior...
Although this game is pretty fun, it eventually gets pretty repetitive and you realize that the game play goes extremely slowly... make a skip animation button or something...
The game is way too easy =.= beat it on my 2nd try without knowing that i could ride on dragons (was avoiding them lol) Didn't realize I could ride on dragons until i accidentally 'hit' one...
My strategy was to have 1 of each sentry and have 1 walker and 1 samurai
Reason? Sentry basically annihilate everything that gets near it, the mortars weaken them off, samurai's get more area to place more sentry and walker stalls the attacking stuff while sentries polish them off =)
I slowly moved up until my mortars were in range and slowly killed off the boss