Here is the full list of all 44 Idol Hands 2 achievements.
First time entering the game.
Unlock Summer's CG
Massage Rainie's feet
Unlock foot sex with Rainie in the gallery
Event trigger: Rainie's masturbation
Unlocked after Rainie's first sex with the protaganist
Event trigger: Rainie's oral sex at the KTV
Event trigger: Having sex with Rainie on the beach
Event trigger: Having sex with Rainie in office outfit
Fuck Rainie in Virgin Killer sweater
Event trigger: Having sex with Rainie in maid dress
Event trigger: Having sex with Rainie in leather outfit
Event trigger: Having sex on the stage with Rainie in stage outfit
Unlocked after Evelyn massages the protaganist
Unlock Evelyn's woman-on-top position in the gallery
Event trigger: Help putting the suppository into Evelyn's rectum when she's having a fever
Unlock anal sex with Evelyn in the gallery
Event trigger: Secretly having oral sex with Evelyn in the morning
Unlocked after Evelyn's first sex with the protaganist
Unlocked after having sex with Evelyn at the farm
Unlocked after having yoga sex with Evelyn
Unlocked after having sex with Evelyn in qipao at the Cha chaan teng
Unlocked after having feet sex with Evelyn in maid outfit
Unlocked after having sex with Evelyn in reverse bunny girl outfit
Unlocked after having sex with Evelyn in an "Upstanding Citizen" position
Pass the All-Star Battle harmlessly
Borrowed money from Ms. Chen of the car loan center
Starting New Game Plus by passing all levels and saving the game
Earned after Rainie's ending
Earned after Evelyn's ending
Get Summer back successfully
Realizing the truth behind Summer's betrayal
Nominated and won the Golden Tune Awards
Nominated and won the Golden Gong Awards
Nominated and won the Golden Pony Awards
Money earned > 1 million
Money earned > 5 million
Dream Manor purchased
Rainie's full outfit collection in the dressing room
Evelyn's full outfit collection in the dressing room
Triggering Summer's hidden event in April of the first year
Beat Wakari at the All-Star Battle in the New Game Plus
Select Rainie to start
Select Evelyn to start