Here is the full list of all 26 Pixel Puzzles: Japan achievements. It takes around 8-10 hours to unlock all of the achievements on Windows.
All Puzzles Complete!
Tsukubai
Enlightenment Attained
Akai Hashi
Gardens of Nijo Palace
Himeji Castle Gatehouse
Cherry Blossom Over Water
Consciousness Raised
Temple Lanterns
Butsudan
Hiroshima Castle Gatehouse
Koen
Nara Temple Gates
A Mind In Training
Iwakuni Bridge
Osaka Castle
Komainu No Enryakuji
Urabandai Lakes
On The Road To Enlightenment
Himeji Castle
Torii
Stop The Pop... With A FIsh
Red Temple Of Nara
Zen Garden
Komainu No Osaka
Pull It OUT!