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