Shooter - Portal Virus

A boy and a girl have the mission to save the world and try to find all the gems to destroy all portals where a dangerous virus is arriving to the planet.
They have to fight with the death, zombies and all kind of monsters and a dangerous virus , in a fabulous worlds wit full dimensional portals.
All game levels are made from procedural content generation, so every level is generated ramdoly.
It Has three levels of dificulty from beginners to experts.
I hope you enjoy. Go ahead