Here is the full list of all 14 Lovely Planet achievements. It takes around 8-10 hours to unlock all of the achievements on Windows.
Shoot Yourself
Unlock All Stars (City)
Unlock All Stars (Village)
Unlock All Stars (Forest)
Unlock All Stars (Swamp)
Unlock All Stars (Mountains)
Collect All Gun Colors
Find All Hidden Secrets
Find the Dagger with the Pearl Inlay (Forest)
Find the Hungry Samurai (Village)
Drink the Sake (Swamp)
Find the Graves (Village)
Visit the Shrine of Lovely Planet
Parry Projectile at Right Angles