After finishing The Last of Us Part 2 on either Grounded or Permadeath mode, the player gets a new Easter egg for each achievement (via DualShockers).
Introduced in The Last of Us, Grounded is a gruelling mode where restricted resources, no HUD, no Listen ability, and much cleverer enemies dealing out triple damage is a true test of character. Permadeath mode was also added to the game at the same time, which is what you see is what you get. There are a scattering of exceptionally tough sections in The Last of Us Part 2, and scraping through them by the skin of your teeth will feel oh-so-satisfying while in Permadeath mode. “However, if taking on the whole game is too daunting, you can choose to enable Permadeath mode with checkpoints on a per-chapter or per-act basis. In other words, if you die at the end of Day One, you’ll have to play the entire day over again,” explained Naughty Dog.
Moving on, players have discovered that completing the game on Grounded unlocks Joel’s cover of Future Days by Pearl Jam as the credits roll. The song is heard often throughout the game, but this is the only opportunity to listen to it uninterrupted. The Permadeath achievement will unlock Ellie’s cover of Through the Valley. This is the song heard in various trailers and adverts for The Last of Us Part 2. Neat, right? Also included in the Grounded and Permadeath patch were gameplay modifiers, like mirror world, infinite ammo, and 8-bit audio, as well as visual modifiers.
The Last of Us Part 2 is out now for PlayStation 4.