Defenders of Roblox is a story driven survival game where a team of 30 players fend off over 30 stages of zombies created by Cracky4. The game itself is a mix between other games like Contamination, Reason 4 Life, and Undead Nation. However, the game has now mostly relegated, as it is very buggy and is exploited often.
Purchasing this unlocks the Assassin which you can use without renting it with in-game currency.