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 Evelyn
Complete an ending with Emily
Complete Chapter 4
Complete Chapter 3
Open this website
Farm the Golden Karet
Can you pet the dog?
Complete Chapter 2
[Redacted]
Open the website
Complete Chapter 1