There is officially no game released solely titled "Mr. Bones 2: Back from the Past." It is likely you are referring to the cult classic SEGA Saturn game "Mr. Bones" (1996), developed by Ed Annunziata and Zono. The game features a skeletal protagonist who is resurrected, fitting the "Back from the Past" description, or you may have encountered a mislabeled ROM or fan project.
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