Many puzzles require both players to move in a specific rhythm.
Based on the subject line, this appears to be a request for regarding the "Biped Switch" feature found in the Nintendo Switch Profile (NSP) format, specifically used in custom firmware (CFW) environments like Atmosphere and tools like Goldleaf or NX Themes Installer.
Biped is simple to learn but difficult to master. The difficulty doesn't come from enemies, but from your own coordination.