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