Project P.I.T.T. Endings
A spoiler-aware Project P.I.T.T. endings hub that separates verified continuation fixes from the secret-route evidence still awaiting confirmation.
Steam lists ending-labelled achievements and the 1.0.6 patch fixes a case where continuing after the main ending could strand a player. Official sources do not publish a complete ending breakdown, so full step-by-step ending requirements are deferred.

Verified continuation fix
Update 1.0.6 says that a player who finishes the main ending should no longer be stuck when continuing the last save. That confirms a current post-ending recovery change, not a detailed completion route.
Achievement status
The public Steam list includes END? and END!, but it hides their descriptions. The two labels are not expanded into an asserted main-versus-secret mapping without a reliable first-party statement.
Spoiler-safe next step
The Secret Ending page presents the evidence sequence and flags missing proof. Save current progress before experimenting with an ending route, especially when a patch has recently changed continuation behavior.
Primary source: Official Steam news — Updates 1.0.5 and 1.0.6 ↗. Scope: full game.