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