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
Gardens of Nijo Palace
Himeji Castle Gatehouse
Akai Hashi
Cherry Blossom Over Water
Consciousness Raised
Temple Lanterns
Butsudan
Hiroshima Castle Gatehouse
Nara Temple Gates
Iwakuni Bridge
A Mind In Training
Osaka Castle
Komainu No Enryakuji
Zen Garden
Koen
On The Road To Enlightenment
Komainu No Osaka
Red Temple Of Nara
Himeji Castle
Urabandai Lakes
Torii
Stop The Pop... With A FIsh
Pull It OUT!