Here is a video of a playthrough for this map as created by JordyBe.
His card levels were Gatling (1), Mana (7), Thunder Moose (6), Clarion Call (7), Froststorm (3), Guardian of Time (7), Furnace (3), Sapphira (7).
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Many players will not have Gatling tower but they can replace that with another high level tower in their deck such as Lightning, WoS, Volcano, Pirate, etc.
My appreciation to Jordy for giving permission to share his strategy.