It seems to me the most common player situations would be these: It just seems so weird to me to have an acknowledgment of 'unlockable' games that are of a different nature, and not otherwise heavily advertised alongside the main game.

When I think of traditional 'unlocked' games, it's usually a variation on the main game some easter egg of a smaller game within a larger one or some surprise hidden IP/license that's not advertised. Can anyone - anyone?! - explain why they'd make those games 'unlockable?'