Here is the full list of all 23 SpunkStock: Music Festival achievements.
Complete Samga
Complete all openers.
Complete Samga2
Complete all co-headliners.
Complete Samga3
Complete Samga3 as the dom.
Get 100% Scene Progress
Impregnate every possible character.
Get your first SS-Coin.
Get 19 S-Coins.
Get 19 SS-Coins.
Buy the Band of Partnership.
Clean out Yu's Shop
Complete the Gauntlet.
Achieve S on the Gauntlet.
Achieve SS on the Gauntlet.
View both of Cali's tapes.
Complete all of Boba's side quests
Clean out Mei's Shop.
Complete the Haunted Hall.
Complete the Future Fragments cross-over.
Ruth impregnated either Yoni or Fufu.
Unlock "Ayra's Love" drink.