Here is the full list of all 46 Adventure Time: Explore the Dungeon Because IDK achievements worth 1,000 gamerscore.
Complete the first Quest.
Survive a Dungeon segment (exit at Checkpoint)
Purchase something from Choose Goose
Defeat the Demon Cat
Defeat the Chase Boss
Defeat the Ice King
Defeat Gunter's Cat
Rescue the Hyoomans
Survive Goliad & Stormo
Defeat Lemongrab
Destroy the cow centrifuge
Defeat the Gumball Guardians
Defeat the Gum Wad
Upgrade Rowdiness once
Upgrade Thumps once
Upgrade Focus once
Upgrade Imagination once
Max out Finn's stats
Max out Jake's stats
Max out Marceline's stats
Max out Cinnamon Bun's stats
Max out Lumpy Space Princess's stats
Max out Ice King's stats
Max out Lemongrab's stats
Max out Flame Princess's stats
Complete Bubblegum's Quests
Complete Tree Trunks' quests
Complete Susan Strong's quests
Complete Mr. Pig's quests
Complete Starchy's Quests
Use a Special Attack
Enter the Nightosphere
Get Cursed
Travel 15 Floors in one Nightosphere run
Travel 25 Floors in one Nightosphere run
Travel 50 Floors in one Nightosphere run
Perform a perfect block
Grab 50 treasures worth of Treasure in a Treasure Floor
Survive a Monster Floor
Collect every Token
Collect every Sub-Weapon
Upgrade a Sub-Weapon to a stronger Sub-Weapon
Eat every different Food item at least once
Locate every Familiar
Find all of BMO's game cartridges
Pick up every type of Item