The narrator (or narration) is at least partially unreliable in terms of what information is given. Half-truths, excessive embellishment, and outright lies are likely methods of delivery.
Name variations: unreliable narration
The first video game about Unreliable narrator was released on January 31, 1997.
Another obvious case is where the narrator describes events as he knows they happened, but what the player actually plays through may only marginally resemble them. This may be due to a person retelling of their actions but ridding them of some unsavory facts.