The main story, request by request.
The mainline runs through a chain of named "Important Requests" across four regions (each new area also tasks you with rebuilding its Pokémon Center). Expect a few dozen hours to credits, plus a substantial post-game (Mew, the Ho-Oh and Lugia summons, the Team Rocket hideout).
-
01 Rebuild the Pokémon Center
Your first Important Request, and one every new area repeats: gather building materials and recruit Pokémon to rebuild the ruined Center that becomes your home base.
UnlocksThe next request, "Yawn up a storm!", and the gather-build-befriend loop the whole game runs on. - 02
Yawn up a storm!
Raise the area humidity to 100%. A Slowpoke's yawn then makes it rain, which softens the rock trapping an Onix and brings out Kyogre, the first legendary. Befriending Kyogre raises your Trainer rank.
UnlocksBoth Bleak Beach and Rocky Ridges open at once; tackle them in either order. -
03 Brighten Things Up
Light up the dark harbor by restoring power: build a Charging Station and wire up furnaces and windmills. Peakychu's Illuminate then draws in Raikou, whose thunder finally wakes the moss-covered Snorlax, Mosslax.
UnlocksClearing this and Rocky Ridges opens Sparkling Skylands. -
04 Time to Party!
Raise the party Mood to 100 with DJ Rotom on the decks and a Hype-specialty Pokémon like Ludicolo, then help Chef Dente cook a Party Platter: 15 Leppa Berries, 15 Wheat, 15 Beans, and 5 Honey. Throw a second party later and Volcanion shows up.
UnlocksClearing this and Bleak Beach opens Sparkling Skylands. -
05 Rebuild the Huge Building
Rebuild the old Silph Co. tower floor by floor (2F, then 3F, then 4F), with Tinkaton's help. Mewtwo appears on the finished roof.
UnlocksThe finale, the Team Initiation Challenge. - 06
Do the Team Initiation Challenge
Back at the Wasteland, the finale comes in several parts. It asks for Environment Level 5 in all four areas plus items like two Party Poppers and a cherished photo. The strange coastal building turns out to be a Team Rocket rocket and blasts off into space; a hidden hideout opens afterward.
UnlocksPost-game: the Team Rocket hideout, the 27-slate Mysterious Mural (Mew), and the bells for Ho-Oh and Lugia.