- "On the night of the full moon the experiment begins."
- ―Unknown girl[src]
The singer of the song talks about performing an experiment on the night of a full moon, and attempting to create a person. She remembers that "they" told her that they cannot return, so the singer must continue with their experiments. The singer describes that she "destroys something and makes something".
The singer recalls that she still hasn't forgotten the words that she first learned, and now it's her turn to teach a new song. On the night of a new moon, the experiment continues. The singer notices that her white doctor's gown has become redder, and continues to "destroy something and destroy again". She reveals that she is trying to create the person who had created her, and with a wish for herself to someday play that game, she states "I’ll be here no matter what, right".
Wordplay shares with Full Moon Laboratory a similar theme of inverting the "Lu li la" lullaby, such as forming it into “La la la lu lu lu."
The Song I Heard Somewhere
The Song I Heard Somewhere shares much of the same melody and lyrics with Full Moon Laboratory, Irina making several callbacks to the experiments performed under the full moon and singing in a similar fashion to the mysterious girl.
Conceptualization and Origin
- Like Tale of Abandonment on a Moonlit Night, Moonlit Bear, and Escape of Salmhofer the Witch, the story takes place on a moonlit night; the moon is often associated with madness and is the origin of the word "lunacy".
- The song's PV is based on the interface of a electronic sound board, with the fluctuating meters and measurements remaining in sync with the song's tune.
- Throughout the song PV, the PV image from Wordplay appears faintly in different orientations and visibility, ranging from faintly visible and upside down to nearly opaque and rightside up.
- At one point during the song PV, the camera focuses on two charts labeled L and R, possibly referencing Rin and Len; interestingly, R is represented by the color red while L is represented by the color blue.
- Similarly, during the first chorus, the song PV is tinted blue while, during the second chorus, it is tinted red; a similar color symbolism is used in Bloodstained Switch.
- The lines "Those words I memorized in the beginning, I haven’t forgotten now" and "So next it’s my turn to teach a new song" are references to Wordplay and Clockwork Lullaby, respectively; the singer also sings "la la la lu lu lu", the pattern sung in Wordplay, instead of the regular "lu li la".
- In-universe, the name of Lunaca Labora means "full moon laboratory" in ancient Leviantan.