The announcement was made by game designer Noel Berry on Medium. In the post, he announces that the game is no longer in development, expanding on their reasons why and where they will go from there:
"There's a bunch of reasons, but the main one is Skytorn just never figured out what it was."
Berry expands on the conflict in greater detail. The game was originally meant to be an adventure game with procedurally-generated worlds and no permadeath. The team found that this rubbed poorly with the Metroidvania heritage it also drew from.
"If we were to finish Skytorn I believe it would require us to throw away a lot of the code & gameplay design. A lot of aspects could be kept our story, the art, the sounds & music, the general theme but the gameplay would need to go."
Berry believes that the team learned a great deal from the experience, however, and look forward to applying that knowledge to future titles.
Skytorn began development in 2012, with a preview video releasing in 2016 showcasing the development's progress. The game held a darker, more sinister and sci-fi design, featuring H.R. Geiger style monsters and a predominantly female cast. Progress was put on hold in 2017 to focus on Celeste, a puzzle platformer released in 2018 that would go on to win the indie hearts of countless players.
Our sympathies go out to anyone who was looking forward to the game. It certainly had my attention. We wish the team the best of luck with their future titles, all the same.