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Today, we have elegant solutions. Emulators like Kega Fusion and RetroArch support "lock-on" natively by loading two separate ROMs. The fan-made Sonic 3 Complete hack uses a 4MB combined ROM without padding. sonicknuckleswsonic3bin game file
Only by combining the games can you access the hidden "Hidden Palace" stages to turn Chaos Emeralds into Super Emeralds [5.31]. You're looking for information on a classic game file