Here is the full list of all 25 Klonoa Phantasy Reverie Series achievements. It takes around 10-12 hours to unlock all of the achievements on Windows.
Complete the Chamber o'Horrors
Unlock all Achievements
Defeat the King of Sorrow
Collect all Momett Dolls
Defeat Cursed Leorina
Defeat Polonte the Hatchling
Defeat Mobile Tank Biskarsh
Complete the Chamber o'Fun
Collect 6 Momett Dolls
Defeat Leptio the Flower Clown
Defeat Folgaran the Armor Beast
Complete the EXTRA VISION
Free all residents in Phantomile
Free all residents of Wind Village
Free all residents of Jugpot
Defeat Nahatomb
Free all residents of Cress
Defeat Ghadius
Free all Residents of Coronia
Defeat Joka
Defeat Baladium
Free all residents of Forlock
Defeat Gelg Bolm
Defeat Evil Seadoph & Evil Pamela
Defeat Rongo Lango