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