a few points
Auto switching to a new gun was annoying. The guns didn't seem to progress normally in goodness, which I suppose is no big deal, except having to be switched to a chainsaw shooter that does nothing when you are in a horde. Not switching to a new gun automatically was little annoying but that's not a huge deal. Having the link pop up instantly on gameover was annoying because I think players will be clicking as much as they can still at that point. It's essentially auto linking.
The game overall was very well put together and polished.