Love Lab

Love Lab (恋の実験室) is the 4th Rhythm Game of Stage 4 (19th overall) in Rhythm Heaven.

Gameplay
The male scientist gets a flask tossed to him. He will shake the flask a number of times and toss it to the female scientist, controlled by the player. The flask must then be shaken to the same rhythm as the male scientist by sliding the stylus back and forth, and then tossed to the scientist off-screen with a flick. If the flask was shaken correctly, all of the hearts made by both scientists will be combined and fall into the white bag.

Timing Display

 * Perfect!/Ace!: The flask is successfully grabbed, shaken and then tossed to another scientist. If shook perfectly, the player will look at the senior lab partner and blush. The hearts will combine and fall into the white bag.
 * Early!/Late!: Grabbing the flask too early or too late will result in a heart either not coming out or floating away. If throwing the flask too early or late, it will cause the hearts to float away even if shaken correctly.
 * Miss...: The flask is not grabbed nor tossed, instead falling onto the counter and breaking into pieces. If the player holds the flask and does nothing, or shakes off beat, their hearts will not combine with the senior lab partner's hearts and float away instead. The senior's hearts, if left uncombined, will dissipate into skull shaped vapors.

Trivia

 * This game takes place in the daytime during the practice and Remix 10, and at sunset during the real game.
 * The game shares this trait with Double Date.
 * Both time settings are used in Remix 4.
 * During practice, the characters do not move to the music.
 * The characters do move to the music during Remix 10, however, despite it using the same textures as the practice.
 * Love Lab Unused Sprite.png guy in the costume has a full sprite, but most of it remains off-screen.
 * The hearts that come out of the flasks also tell you whether you were early or late. If it's a bit over the heart produced by your partner on the left, you grabbed/shook the flask early. If lower, you were too late. If it's right where the heart/hearts are before, you hit it just right.
 * This is only one of three games in Rhythm Heaven to appear in only two remixes.
 * The others are Love Lizards and Rockers.
 * There is a different opening banner in the Japanese version featuring an AIAIgasa (相合傘),which is the act of sharing an umbrella that can be considered romantic in Japanese culture. Whereas, the international versions had pink and blue abstract text spelling "Love Lab", along with a pink flask moving to the center in a choppy way.
 * A slightly different version of the "Try Again" screen exists in the game's code, with the characters' lab coats being drawn differently.