Here is the full list of all 42 Winter Dream achievements.
Finish Rose's route with her as your girlfriend.
Don't help the young kid.
Hang out with Rose twice on the third day.
Don't make any friends during your vacation.
Tell a story at the orphanage.
Juggle at the orphanage.
Put an a play at the orphanage.
Confess to Rose.
Finish Rose's route with her as your best friend.
Tell jokes at the orphanage.
Agree to being best friends with Rose.
Help the young kid.
Hang out with Gwen twice on the third day.
Hang out with Velda twice on the third day.
Say Gwen is cute.
Respect Gwen's privacy.
Don't respect Gwen's privacy.
Admit to being curious about Gwen.
Get Gwen to despise you.
Let Gwen know that you're friends.
Confess to Gwen.
Finish Gwen's route with her as your best friend.
Finish Gwen's route with her as your girlfriend.
End up with Velda leaving.
Think about Velda when you're in trouble.
Stay behind when Velda leaves to save Gwen.
Go with Velda to save Gwen.
Get the worst ending for Velda.
Finish Velda's route with her as your best friend.
Finish Velda's route with her as your girlfriend.
Get the worst ending for Gwen.
Get Gwen's neutral ending.
Call Velda a bitch.
Promise to keep Velda's secret.
Confess to Velda.
Tell Velda that you want to be friends.
Lose your friendship with Rose by being a horrible person.
Get the worst ending for Rose.
Give up on life.
Learn the truth about Caron and their world.
Reject Rin's offer.
Save Caron from his fate.