Geometry Wars Galaxies on Wii can be linked with Geometry Wars Galaxies on Nintendo DS (both released in 2007).
If the handheld version is connected to the console version, the LAMBDA Galaxy gets unlocked. This exclusive galaxy consists of 7 new planets, aka stages, and each one has its own theme and gimmick.
Also, the Wii version can send the full version of Geometry Wars Retro Evolved to an empty DS, which was first made popular on Xbox Live Arcade. The DS version can also send this game to an empty DS. The DS version has single-card wireless multiplayer support too.
