Here is the full list of all 15 Emily is Away <3 achievements. It takes around 12-15 hours to unlock all of the achievements on Windows.
Complete all major endings
Complete an ending with Emily
Farm the Golden Karet
Can you pet the dog?
Complete an ending with Evelyn
Open this website
Complete Chapter 4
Complete Chapter 3
Complete Chapter 2
[Redacted]
Open the website
Complete Chapter 1