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