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