The game is quite fun to play, but here are some thing you might want to improve on:
1)Since the map is so big, perhaps an indicator at the edges of the screen for off screen monster would make it easier to navigate.
2) Since the map has a limit and there is nothing after it, perhaps make boundaries there so that player can not pass them.
3)Perhaps make it so you can kill cows only with one of the weapons, because quite often while trying to kill the enemies I killed the cows as well.