I think its a well rounded game and is fun to play. For me personally the spawnrate was quite slow which in turn slowed down the game as well but thats only nitpicking. I liked the subvertion of expectation at the begginning as well.
We agree. An alien spawn when you throw one. We had the idea to change it with a timer but it was to late to make the change in the weekend (we had more prior bug fixes to handle eheh)