Why HBO shelved Game of Thrones prequel Bloodmoon?

As A Knight of the Seven Kingdoms revitalised the Game of Thrones world, long-standing prequel plans that never progressed past the development phase.

The lead-in has also come back into focus, such as the planned series Bloodmoon that HBO planned to make and eventually abandoned.

The scrapped project, directed by Naomi Watts, was set in the Age of Heroes, well before the action of Game of Thrones. 

The tale was an attempt to explore the Long Night and track the ancient mythology of the White Walkers. 

However, regardless of the magnitude of the ambition, HBO decided not to move ahead after evaluating the pilot episode, that is to test concept viability.

The Hollywood Reporter then clarified the decision by a later interview with Robert Greenblatt, the former chairman of Warner Media.

"It wasn't unwatchable or horrible or anything," he marked.

Continuing, "It was very well produced and looked extraordinary. But it didn't take me to the same place as the original series. It didn't have that depth and richness that the original series' pilot did."

It lacked the depth and richness that the pilot of the original series had; additionally, the creative expectations were structural problems with the show.

George R.R. Martin had given minimal written information regarding that time period and much of the world-building was left to the creative team. 

He himself admitted that this was a challenging task, saying to THR, "'Bloodmoon' was a very difficult assignment,"

"We're dealing with a much more primitive people. There were no dragons yet. A lot of the pilot revolved around a wedding of a Southern house to a Northern house, and it got into the whole history of the White Walkers."

Jane Goldman created Bloodmoon, which allegedly had a price tag of 30 million dollars for the pilot, a price no one would risk to gamble, yet ended up being a costly gamble that did not favour HBO.

Related: 'Game of Thrones' prequel release date announced: Spoiler Alert