Do you guys know if the Monster's Difficulty are really increased on Level 7?
(even a Grenade can't kill a regular zombie)
Level 1-6 Easy
Level 7-11 Hard
Level 12-??? Normal
Yes, as the waves progress, their HP and damage increases. New monsters are also introduced eat wave. I think, by wave 12, the monsters no longer get stronger and certain monsters stop spawning.
What do you think?