i wonder if this is a mix of zerd, terrain and protost :)
Good game but some how it lack a complexity, i mean i can just spam just flasher and guardian (as meat shield) to be done with everything even in hard. Big food not really that strong compare to destroyer ( flasher is squishy but they wrech every platform with their atk).
Air force need more context, like Thunder weak enough to be beaten with just 3 guardian compare to the cost, if it just scout unit with least cost then may be it will work ( and only AI stupid enough to let you back stab them with only Thunder)
Auto repair tower though it a good idea but it regen too fast. if an attack fail, that tower will be in good health without any cost ( see how slow the zerd building regen?)
And there is a bug ( normally if i use Thunder to atk, every thing disappear, dont know if it froze or not, but if i move my camera away it normal again, but when i return to battlefield it happen again after 2-10s.)
Overall it a nice work but still need more work, i look forward to your Multiplayer and upgrade :)