A great entry for sure. Loved the concept, and the execution is very well done.
The horde attacks were quite hectic, but after a couple of restarts, I finally got a better strategy for dealing with those. The scaling out of the map was a cool addition, to scale the difficulty up as you went along. Initially it felt like it scaled up way too fast, but playing a few more times and getting better at the game essentially made it a lot more manageable, so that's probably fine as well.
Don't really have anything else to say about this, other than this was great, and nicely done!