Every day you are being watched by these brain eaters. Survival depends on accepting your fate as a zombie hunter. For every zombie you kill, you get different points. Also, your weapons will be improved. Therefore, you will be motivated to kill as many zombies. Go through the portal to improve your weapons. Shoot each zombie that stands in your way. Show no mercy. Nobody is exempt from this fate. You're the only one who can keep up with all the zombies. Do your best. Zombie will attack from all sides, so be careful.