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