There's also Dwarf Fortress[0].

0: http://bay12games.com/dwarves/

That one is technically a two-man band, but definitely still fits the pattern of someone dedicating their life to making a complex game.

To the credit of GP, in DF there occurs exactly the type of obsession (in dwarfs) that the original commenter talked about, so it's worth a mention even if its "single creator" is two brothers

And also the venerable RollerCoaster Tycoon

https://en.wikipedia.org/wiki/RollerCoaster_Tycoon_(video_ga...

sawyer contracted out for the art (Simon Foster) and music (Allister Brimble). still a heroic individual effort though

Especially given that he wrote the whole thing in assembly.

And Touhou.

The Windows series of games are 16 years old today

It's still pretty successful worldwide, with major fan conventions and contents being released in PS4, Steam, etc. Quite an interesting phenomenon.