Gameboy non oem, Mega Man 1 video game cartridge. Game cartridge comes with a plastic protective case just like the picture shows.

The first Mega Man title for the Game Boy, officially titled Mega Man: Dr. Wily's Revenge, was released in 1991 as a handheld remix of the first two NES entries. Rather than being a direct port, it features a unique structure that combines elements from both console games with original additions. 

Key Gameplay Features

• Split Boss Lineup: The game begins with four Robot Masters from the original NES Mega Man—Cut Man, Ice Man, Fire Man, and Elec Man—available to fight in any order.
• Wily Castle Twist: Upon reaching Dr. Wily's fortress, players encounter four additional bosses from Mega Man 2 (Quick Man, Bubble Man, Flash Man, and Heat Man) in a teleportation room.
• Exclusive Boss: The game introduces Enker, the first "Mega Man Killer" robot, who can absorb incoming shots with his Mirror Buster lance and fire them back as a powerful beam.
• Visual Design: The sprites are notably larger and more detailed relative to the screen size compared to the NES versions. While this provides higher fidelity, it results in a more cramped "zoomed-in" view of the levels.
• Challenge Level: It is widely considered one of the more difficult entries in the series due to pixel-perfect jumping requirements, large character sprites making it harder to dodge, and a lack of helpful items like Energy Tanks that appeared in later sequels. 

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