It is the day after tomorrow, humanity is dying and the zombie race is taking over the world. Survive by scavenging cities for food, items and weapons. Increase your skills, construct, build and improvise, assemble your own car and turn it into a death-mobile. Befriend other survivors, tame and train animals.
Craft, combine and modify various weapons from spears, knifes, swords, crossbows and longbows to pistols, rifles, snipers, grenades, molotov coktails, flamethrowers, railguns and laser rifles. Or learn martial arts and fight monsters with bare hands!
And if you manage to survive you may find exciting things such as bionics, which can give you amazing powers not usually seen in mortal hands. Or you may gain a mutation, usually bad, but sometimes very very good. Who knows. Remember to keep your spirits up, but try not to overdose on drugs or alcohol!