You are trapped in the building and are being attacked by the worms and ghosts. Equip your elevator with heavy artillery to fight against the enemy. You can buy items by clicking on them. You should earn some cash to do that. You can also sell or upgrade your existing weapon. Buy extra elevator which will help you to fight against the attacking worms on different levels of the building. The more you kill, the more money you will make. Try not to get caught in the falling lift otherwise the game will be over. Protect the elevator shaft at all costs.