Splashdown (シンクロ,Shinkuro?, "Synchro") is the 21st minigame in Rhythm Heaven. In this game, you are playing a Synchrette who is doing some synchronized swimming with the other two Synchrettes to the beat. The sequel, Splashdown 2, is unlocked later on.
The player controls the Synchrette on the right and must move in sequence with the other swimmers by holding the stylus on the touch screen to dive underwater and lifting it to rise to the surface. At certain points the Synchrettes will have to jump out of the water in sequence or together at once on a dolphin or by being tossed in the air by other swimmers, the player must flick at the correct time to successfully jump.
Tap: Dive underwater.
Release: Surface from underwater.
Flick: Jump out of the water with a dolphin.
Hit: The player's Synchrette successfully dives underwater. When jumping out of the water, the Synchrette and her dolphin will perform a flip or the Synchrette tossed will exclaim "Ally-oop!".
Miss: If the player misses their cue, a 'doink' sound will be heard when they dive underwater. If the player rises from the water off cue, their Synchrette will flail out of the water in panic. If the player launches out of the water off cue, the Synchrette will pop out hanging onto the dolphin's tail both having worried looks or the tossed Synchrette will be flailing in the air helplessly.