Because the game was built for the Nintendo DS, it uses hardware features that the Neo Geo cannot support, such as the used for level mapping and prisoner tracking.
As for Metal Slug 7 , let go of the Neo Geo dream. Instead, grab Metal Slug XX on Steam or Switch—you’ll get online leaderboards, HD visuals, and a clear conscience. And if you still crave the dual-screen experience, with a legally backed-up ROM is your true answer. metal slug 7 rom neo geo
You need a .nds ROM file, not a Neo Geo zip file. 2. Metal Slug XX (The Arcade-Style Upgrade) Because the game was built for the Nintendo