Here is the full list of all 22 1HEART achievements.
Complete the game
Find all hidden hearts in the game
Listen to seven hidden tracks
Check all console commands
Check "The Pirate Bay" site in computer console
Find dissecting room in less then 2 hours
Get to basement without hints
Listen to four hidden tracks
Open door leading to the church basement
Find half of the hidden hearts
Destroy all possible crates
Kill sheep
Play 1Heart for one hour
Solve ancient ornament riddle
Enter the church
Pass the river
Solve hidden object puzzle without hint
Make 200 mouse clicks
Complete the tutorial
Make 2000 mouse clicks
Make 5000 mouse clicks
Play 1Heart for more then three hours