This Small day 1 update is just a last few touch ups to the game. There was a few songs missing both in the game and the soundtrack and those have now been added. That is all~
Small Day 1 patch, Music Patch
Source: Steam Community (opens in a new tab)
Build and release context
Recorded Steam release date:
Within one calendar day of this post (UTC). The listed date does not establish an exact launch time.