Here is the full list of all 21 Lost Words: Beyond the Page achievements worth 1,000 gamerscore.
Found all the Fireflies
Played to the end of the credits
Started something new
Finished Chapter 8
Lit all the torches in E8
Unlocked your full potential
Finished Chapter 7
Finished Chapter 6
Knocked every frozen Seakin over in E6
Collected every black asterisk
Finished Chapter 5
On D5.5, finishing doing all the washing up
Finished Chapter 4
On D4.13, threw the pie to the left have it loop around the screen to the first line
Finished Chapter 3
Finished Chapter 2
Helped the trapped villager in E2
Collected the items in Estoria 1
Looped a diary page for 5 secs
Finish Chapter 1
Rang the bell in E1