Developed by the same team that created Club House Games on Nintendo DS, Slide Adventure MagKid (2007) was a Nintendo published DS game that turned the dual screened handheld into a computer mouse.
By attaching the special mouse peripheral into SLOT-2 (the GBA cartridge slot at the bottom), players slide their DS like using a mouse instead of using the D-Pad or touchscreen. There are a few main gameplay modes, mini games, and multiplayer options available. Sad this is a one-of-a-kind accessory wasn’t used in other games.
Smash Bros. Ultimate on Switch has a reference to this forgotten Japan exclusive DS game too.