Undone Studios™/Infection Inc.

Infection Inc. is a tycoon game made by the group Undone Studios™. The group is owned by, along with and  as its lead developers and about 9,500 members in total. As of February 4, 2018, the game has reached over 19,000,000 visits, 300,000 favorites, and a 76% approval rating.

Infection Inc. revolves around the silly idea of competing corporations trying to make a profit by infecting their citizens with zombies. Your goal is to dominate the world with the strongest zombies, while also sabotaging other corporations' progress (i.e. killing a zombie made by another competing corporation using a melee/ranged weapon.) The main currency in this game is the Credit, earned by killing/probing the humans, earned via minigames, or you can buy a fixed amount of credits using Robux.

Gameplay
At the beginning of the game, you start off with a manual zombie spawner, which slowly creates a zombie every time you press on the machine's button (15 Button Pushes = 1 Zombie). Every time you create a zombie, that zombie goes onto the road to eat humans. For each human it kills, you gain money. As the game progresses, you can upgrade the stats of your zombies. Once you have enough money, you can upgrade your base. This can be done by stepping on the buttons on the ground, signified by their use and cost, once you have enough money. Red buttons signify zombie spawners, blue buttons signify decorations, and green buttons signify upgrades that cost robux, yellow/orange buttons signify decorations that can be bought using rebirths, and the Purple buttons (seen on the ground floor) signify morphs and accessories.

You can either play silently by focusing on upgrading your base, or you can go out and kill zombies made by other corporations as an act of sabotage, however you should note that you can't make money off of killing other zombies but instead you will send money to the zombie's owners every time you kill one (The money sent will not deduct your credit balance), the amount of money that goes to the owner of the killed zombies depends on the type of zombie killed.

There are minigames you can play that will give you credits when you manage to win. These minigames appear occasionally. There are currently 2 minigames that are playable, Zombie Defense, and Apocalypse Racing. You can play these via the Minigames Tab on the left side of the screen.

Zombies
There are currently 4 types of zombies, the Normal Zombie (Jack of All Trades, Master of None), The Runner Zombie (Specializes in Speed), The Hulk Zombie (Specializes in Health and Lifespan), and The Stalker Zombie (The Paranormal version of the Normal Zombie). The Normal Zombie is the beginner's zombie and is found in the first floor. The Runner Zombie is found in the second floor. The Hulk Zombie at third. The Stalker Zombie at fourth.