Zombie Combat Simulator

- A new option for unlimited ammo has been added to the sandbox mode;
- The ability of the mercenary has been changed. It will now increase the maximum HP and speed up recovery, but it will no longer be able to heal teammates;
- BOT now has the ability to heal teammates, which is the same as the mercenary’s ability in the previous version;
- The difficulty of Nightmare Evacuation Mode will increase by two after winning a round in a row;
- Further fixed some zombie control issues;