- The correct name for this song is #4 dunno. The substitution of the # symbol with the "fullwidth" ＃ symbol is due to technical restrictions.
#4 dunno is a short, quite mysterious-sounding, with some sound effects repeated throughout the song. There is an instrumental section at the start before the instrumental changes. The song has a very fast temp as well as a strange time signature, making it sound quite disorientated. The song uses only synthesis instruments. The song can only be heard in the Octo Expansion, and is generally heard in stations with a focus on the destruction of crates, such as Breakdance Station, One-Shot Station, Matchmaker Station, Matchmaster Station and Footloose Station. It is also heard in Swass 8-Ball Station.
Dunno is slang for "I don't know", possibly referring to some of the stages that this song is played in, which require patience and thought-out strategy.