What does the phrase "Tubular Journey" mean here?

Please help me figure out the meaning of the phrase "tubular journey" that is used as a title of a running game's description.

I know the lexical meaning of the word "tubular", but it doesn't seem to fit here.

The main character continuously runs in a city that reminds one of 70's decade. Does the word "tubular" have a connection to that decade?

Solution 1:

"Tubular" was originally surfer slang in the 1970s, meaning "awesome". It later spread more broadly among young people in California in the 1980s, and then became hopelessly passé.

It's discussed on this web page of 80s slang.

It seems quite likely this is the meaning of tubular journey the OP is asking about, especially if the city in the game at all resembles LA in the 1970s.