Vidmaster Challenge: Endure
From Halopedia, the Halo wiki
Vidmaster Achievement: Endure is an achievement in Halo 3: ODST and one of the Vidmaster Challenges. It is unlocked when you play on Firefight, on any mission, and pass the 4th set (the 12th round and 60th wave) on 4 player Heroic co-op Live. It is worth 25 Gamerpoints.[1]
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