Here is the full list of all 27 Bokida - there are Heartfelt Reunion achievements.
Reach the 100% completion mark
Read all the words of the Way
Gather all echoes of the Dark planet
BUILD 10000 blocks over the course of one game (same save file)
CLEAN 20000 blocks over the course of one game (same save file)
PUSH 20000 debris and fragments over the course of one game (same save file)
CUT 20000 blocks over the course of one game (same save file)
Unlock the ability to return to nothingness
Read half the words of the Way
Clear 3000 debris and fragments with a single CLEAN
Push 1000 debris and fragments with a single PUSH
Cut through 1000 blocks or more in a single CUT
Collect 40 echoes of the Dark planet
Unlock the ability to control the flow of time
Boost 50 consecutive times without touching the ground
Remain airborne for 90 seconds or more
Reunite Light and Dark, causing Two to be as One once more
Collect 25 echoes of the Dark planet
Complete the Haven monolith
Read 10 steles bearing the words of the Way
Complete the Highlands monolith
Unlock the ability to turn the balance of the world upside-down
Complete the Temple monolith
Unlock the ability to shatter blocks
Reach maximum velocity
Complete the first monolith, allowing the Light planet to reveal itself
Restore all the links between Light and Dark in less than 20 minutes