Metal Slug Mobile 4 is a run 'n' gun game developed by SNK Playmore for various cellphone models.
During development, the game was called Metal Slug: Survivors.
This game is radically different from its mobile predecessors, as it was upgraded with enhanced graphics and playability, as well as music playing during the stages. Players can select from two new recruits: Leona Heidern, from The King of Fighters series, and Roberto, a new character made for this game. Players must fight their way through four stages split into four sections each, with the last section being a boss battle.