Updates to the achievement artwork will be coming. All achievement unlocking functionality still works fine, just the icons are all placeholders currently. This was something I intended to update alongside version 1.01.
Thanks for reading!
-Mikey
Updates to Achievement Artwork on the Way!
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.