Beast Shooter: Mezase Beast King is a Japanese exclusive Konami GBA title that features a Single-Pak link multi-boot mode. Unfortunately, without an English patch, it is difficult to determine exact gameplay details but I did manage to find two Single-Pak link modes as I stumbled my way through the main menu.
Gameplay is basically like Olympic Curling only with mechs. Using a directional meter, you need to bump your opponents off the stage or deplete their health. There are cards to play and some tiles on the stage are colored but couldn’t figure out what these do exactly since I do not speak Japanese. If you know more about this Japan exclusive, let me know in the comments.
This is Single-Pak link!