Here is the full list of all 48 Solitary PaperPlane achievements.
You have played the game for 15 minutes
You have played the game for 30 minutes
You have played the game for 1 Hour
You have played the game for 2 Hour
You have played the game for 3 Hours
You have played the game for 6 Hours
You have played the game for 12 Hours
You have played the game for 24 Hours
You have played the game for 1 Week
You have played the game for 1 Month
You have played the game for 1 Year
You have collected 1 Ring
You have collected 10 Rings
You have collected 50 Rings
You have collected 100 Rings
You have collected 200 Rings
You have collected 500 Rings
You have collected 1000 Rings
You have collected 2000 Rings
You have collected 5000 Rings
You have collected 10000 Rings
You have collected 20000 Rings
You have collected 50000 Rings
You have collected 100000 Rings
You have played the game for 2 Hours