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