There are some really cool ideas here, but some of the technical and UI issues (especially on mobile) are hard to get around. In general, I wish the screen size was a lot more responsive to the user's device; I started reading the guide on my phone, but the text was so tiny, it was near-impossible to read. I know what a pain in the ass WebGL development is with Unity, though, so I realize that most of your time during the jam probably went to the game itself - and it shows! It was cool to see different kinds of weapons and bigfeet, and the interplay between them.
One other UI-related thing that comes to mind is that it can be confusing if you're trying to lay down a unit, but you're trying to do so in an invalid location (i.e. in the middle of the road). At first, I was confused as to why I couldn't lay down the unit, since I was pressing the green checkmark - maybe it would help if the green checkmark didn't show up at all if you're unable to put down the unit? Having just the red checkmark (or even just changing it to a red X) could make it clearer that you've chosen an invalid location.
All that said, I think you did a pretty good job for the time you were given, and especially by yourself!