Oxenfree 2: Lost Signals features a short list of collectibles: a set of 13 Adler letters that the protagonist's partner, Jacob, buried when he was a kid. Digging up the full set will give players the achievements "A Flash of Green," "Peace in this Ocean," "Among the Headstones," "Orphaned Dreams," and "One Last Mystery."
Each letter reveals a little more about Adler and the setting, and finding the last one will start a unique conversation between Jacob and Riley. Players can find each collectible in Oxenfree 2 by looking for small, blinking lights located in almost every region of the game and pressing the interaction button while standing on top of them. However, they only start appearing once players get the climbing equipment from the general store, and a few have some extra requirements.
Uptown Harbor
Players can find the first Adler letter immediately after getting the climbing equipment. Go up the hill behind the general store and check behind the flagpole.
Highway by Funnie's
This area is called Funnie's, the Highway, or the Parking Lot depending on what players check. Regardless, reach it is by following the auto road out of Uptown Harbor. The Adler letter is right below the dumpster.
Copper Creek Trail
Take the upper exit from either Funnie's or Uptown Harbor to reach Copper Creek Trail. This is the area where players meet Jacob. Climb the rock wall on the way up to Pemmican Trailhead to reach an Adler letter. Players can also leave Pemmican using the southeast exit to reach this letter.
Pemmican Trailhead
Take the northwest exit from Copper Creek Trail to spot this letter. It's across a fallen log near the entrance that otherwise leads to a dead end.
Camber Cape
Players have no reason to return to Camber Cape after getting the climbing equipment, but those who do will find an Adler letter in front of the animal den near the summit.
Waterhead Bluffs
When players reach the climbing sequence where Jacob refuses to follow Riley, climb up to the ledge and jump to the right instead of to the left. These ledges lead to a trail with an Adler letter at its end.
Charity Point
As players are climbing up from the Waterhead Bluffs, jump across to a platform on the right instead of heading left towards the bridges. There's an Adler letter on the ground over here.
Point Tilia
First Letter
Unlike every other area in the game, Point Tilia has two Adler letters players can collect. Finish the sequence with Charlie in this area, then head left past the waterfall. Climb up towards the observation point, then follow the trail left and climb down a rock wall to get the first Adler letter.
Second Letter
The second Adler letter is close to the ranger station. Instead of going up the trail to the station, go right along the barely visible trail and climb onto the log to reach the isolated area with the Adler letter.
Horseshoe Beach
This Adler letter only shows up once players have placed the transmitter in Tootega Falls. Instead of going straight back to Point Tilia, head down to the beach to the right of the natural bridge and go right to the edge of the water.
Tootega Falls
This Adler letter also won't appear until after the story in this region is complete. It shows up on one of the stones at the base of the falls.
Garland
The last regular Adler letter is in the ghost town of Garland. Head up the stairs behind the cemetery to reach it.
Berenson Creek
The thirteenth and final Adler letter only appears once players have collected all 12 of the other letters. Players can collect these other letters in any order, but the letter in Berenson Creek is always the last one. To reach it, descend the stairs in front of Jacob's cabin to reach his shack. The letter is just beneath the metal sunflower sculpture.
Oxenfree 2: Lost Signals is available now on Android, iOS, PC, PS4, PS5, and Switch.