I see what you did here, an idle version of age of war :)
I finished your demo, I do like Idle games. But something in the game doesn't communicate that it is Idle. It seems too symmetrical, so I kept expecting the enemies to threaten me, which they didn't.
The way I see it, you can go in one of two ways: Make it an age of war style of game, with the enemies actually attacking us. A lot of people like that style of game and you have solid mechanics implemented for this style of game. The other option, is to give it the idle feel. I actually do like the idea of your units getting killed in an idle game, but you have to clarify visually that there is no threat to your base. For example, instead of an enemy army, put a gigantic monster coming out of a swamp and killing whoever comes close. That way we won't expect it to move, and the behavior could be roughly the same.
Anyway, I had fun, good job.