The game has improved a lot since the last few versions but I think adding mechanics to at least reduce the amount of enemies spawning evry day should be in the game. I'm thinking something along the lines of reducing the amount of enemies respawning in an already cleared area so the player can focus on the newer area while not having to completely abandon the already cleared ones. That way the intend of the game design remains while reducing the time bloat of having to spend more and more time with each unlocked area with clearing enemies you have already seen a thousand times over.
i killed 3
and...
author this game the biggest dirty dog ever