The AI for the units is really nice, and I like how you have the hand bounded to a certain region for unit placement. I think with more levels / unit types this would be really good, but you have the core well-designed here. Picking up and moving your units around with the hand wasn't trivial to implement, that works really nicely. And good work on the barricades, as I know getting those to work nicely with the navmesh for the rest of the terrain isn't trivial either.