What made you decide to release a separate free app vs a demo on the original app? Not critiquing the choice, just curious what the reasoning could be.
I looked at the trailers and I think it would be helpful if your towers and other friendly buildings / units have a different coloured orb compared to enemies. I found it very hard to distinguish between friend or foe. That could be less impactful when playing, but first impressions leave me slightly confused. Put it on my wishlist!