Pokémon Mystery Dungeon: Adventures to the Abyss and Journey to the Beyond is a fan idea of the spinoff series: Pokémon Mystery Dungeon. It introduces Generation VII pokémon from Pokémon Sun and Moon.
Like in previous games, the player is a human that has transformed into a Pokémon, and has entered in a world only inhabited by Pokémon. The player loses all of their memories, except the fact that they were human. The player ends up in a mountain that is located in a forest with a lake when they first entered the mysterious world. The player follows the path down the mountain, when they reached the end path of it; four Zoroarks gang up on the player ready to attack them. Unexpectedly, a Suicune dashes to the player letting them go on her back and saves the player from the Zoroarks. The player recognizes the pokémon that saved them from the Zoroarks isn't an ordinary pokémon, but is a legendary pokémon that saved them. Suicune guides the player out of the forest, and leads them to the entrance of a town, the pokémon then informs the player that one day they'll meet again and warns them to watch out from being attacked, Suicune starts to leave the player near the entrance. The player tries to talk to Suicune where's she going and what are they going to do, but no answers were said by the pokémon and already left them behind near the town entrance. The player realizes that they'll find it out by themselves in the town anyways, but is still curious about Suicune when she'll meet them someday.
There is a total of 42 starter pokémon to choose for the player to pick and for their partner.
Like in previous installments, certain shops return from Pokémon Super Mystery Dungeon. The purple Kecleon returns back in Kecleon's Shop after his absent in Gates to Infinity and Super Mystery Dungeon.
- Slurpuff's Sweet Pastries
- Swellow's Speedy Air Mail Delivery
- Forest Hill
- Mt. Magnet Trail
- Cheerful Meadow
- Fairy Forest
- Drago Mountain
- Volcanic Abyss
- Dusk Jungle
- Distorted Dimension (final dungeon)
- It was originally going to be for Generation VI (X & Y), but due to Pokémon Super Mystery Dungeon existence, it was changed for Generation VII (Sun & Moon).