Here is the full list of all 13 Lunaform achievements.
Shield from 100 stars
Unlock all the upgrades
Fill every Hex
Complete the Blackhole
Complete the Luna Planet
Complete the Coran Planet
Complete the Slyph Planet
Bump 1000 stars
Complete the Centauri Planet
Complete the Nymph Planet
Swap 100 times
Beat Centauri3 without taking any hits
Complete the Lunaform Tutorial