The Spectral Castle is an unreleased video game by Giik.

The Spectral Castle appears to be Giik expanding on a GameMaker test.
In a video titled "Wheeee" published in February 2013, Giik shows off “a guy [running] around” with the same sprite that would be seen in TSC devlogs.

Giik shared the game's logo on Deviantart in May 2013.¹⁾

Giik uploaded 4 devlogs. The latest devlog was uploaded in June 2013.

In May 2015, in the super cat planet announcement on raocow's forum, Giik posted a GIF of another personal project, which appears to be Spectral Castle after considerable progress.²⁾

In January 2016, Giik stated he was still working on the project.³⁾

In April 2016, Giik shared a devlog on enemies.

He would quietly drop it to work on other projects. And you know what? Fair enough.