Here is the full list of all 26 Zenodyne R achievements.
Unlock the Fifth Ship
Unlock all the ships!
Beat the game using the second ship
Clear the Final Stage (Ending A)
Clear Final Stage Hard (Ending B!)
Beat the game using the first ship
Unlock the Fourth Ship
Clear Stage 5
Clear Stage 5 Hard
Clear Stage 4
Clear Stage 4 Hard
Unlock the Third Ship
Clear Stage 3
Clear Stage 3 Hard
Clear Stage 2
Clear Stage 2 Hard
Unlock the Second Ship
Clear Stage 1
Clear Stage 1 Hard
Defeat the Commander (Ending C!)
Beat the game using the third ship
Beat the game using the fourth ship
Beat the game using the fifth ship
Unlock unlimited credits!
Unlock all the lore!
Beat the game using the cameo ship!