Heavily inspired by PenguinDoc9999 SIA51. Removed Valentine Event. Portal now cycles instead of random portals. More events to come. tags: Zombie, Area 51, Roblox, Shooter, Survival, Sci-fi, Aliens, Apocalypse, Adventure, Multiplayer, Horror, FPS (First Person Shooter), PVE (Player versus Environment), Action, Defense, Military, Guns, Strategy, Tactical, Cooperative, Open World, Exploration, RPG (Role-Playing Game), Battle, Teamwork, Combat, Waves, Slaughter, Undead, Intense, Campaign, Survivalist, Thrilling, Tense, Frightening, Menacing, Cooperative, First Person, Zombie Apocalypse, Science Fiction, Eerie, Terrifying, Infestation, Post-Apocalyptic, Nerve-wracking, Challenges, Raid, Escape, Panic, Ghosts, Paranormal, Mysteries, Investigate, Military Base, Confrontation, Sci-fi Horror, Space, Armory, Jump scares, Stealth, Perilous, Hazardous, Otherworldly, Survival Horror, Abandoned, Chilling, Infection, Outbreak, Catastrophe, Co-op Survival, Survival Shooter, Tacti