This is a genuine Nintendo Dr Mario Game Boy game, offered boxed in overall fair-good condition including instructions. Although Japanese, the game is region-free, plays with full English text and features a Sharp ROM chip dated week 44 1990. All components are in the condition as photographed:

Game Pak: Fair-acceptable condition. The top half of the plastic case has yellowed, see photos. Front sticker is acceptable, noting slight curling along the top edge. Edge connectors clean and show little use. Screw back in good shiny condition. 

Game Pak case: Good condition. Some light scratches, clear plastic, snaps closed as designed.

Plastic box tray: Good plastic tray, no marks or damage, some yellowing observed.

Instructions: Overall good condition. Instructions are complete. Booklet has a unused feel to it. Inner pages show occasional pale blotching from storage. Please check photos carefully.

Box: Good overall condition. The box has a bright and colourful finish, noting light wear to the top edge. The box flap is fair-good with slight weakness from use. Generally well cared for, from 36+ years of storage. 

This game has been tested on a Game Boy Color for this listing. Game Boy Color is not included.

Dr Mario was a top-selling Nintendo game in the early 90s. This listing offers a great chance to own a small piece of Mario history at a fair price, noting cart condition.

Will be carefully packed in an outer box and sent with Royal Mail 48.

Any questions, just let me know :)