While we don't have specific details, we do know that some new content is coming to Tangledeep. This comes straight from the official Twitter account, which shared the following message.
Coming soon to Tangledeep... a challenge BEYOND New Game Plus?! Not for the faint of heart or the wavering of courage!
Whatever this is, it seems that it'll release in the near future. We'll keep tabs on this and share any subsequent details.