Most of the more specific information comes from aidn, the creator's Twitter account and Discord server.
All of the characters have a confirmed age, birthday, and height.
Key After Key, the composer of most of the soundtrack, has stated that "OVERTIME!?" was meant to emulate the feeling of sheer panic when playing as his main, Biograft.
Other trivia:
The songs "SEE YOU ON", "THE FLIPSIDE", and "STRIKE OF LUCK" feature instruments similar to that used for the sound of Dom and Valk's voices, which suggests they may be singing.
OVERTIME!? is the only original song not replacing a pre-existing song, before this overtime was completely silent.
The "OVERTIME!?" scream was originally going to be a sample from voice actor BanicAttack. The unused sample, however, later went on to become the sound effects for Yulaser's attacks.
The last note of "Pandemonium Coda" and the first note of "OVERTIME!?" are the same.
) in "Rock-a-Bye Bivalve."