Here is the full list of all 30 East Tower - there are Kuon achievements. It takes around 0-1 hour to unlock all of the achievements on Windows.
You've unlocked all of the Achievements!
You've got the Normal Ending!
You've cleared Re-Stage 4 and done a good job!
You've cleared Re-Stage 3 and done a good job!
You've cleared Re-Stage 2 and done a good job!
You've cleared Re-Stage 1 and done a good job!
You've cleared Stage 2 and done a good job!
You've cleared Stage 1 and done a good job!
You've unlocked all of the CGs!
You've got the Bad Ending!
You've cleared the Love Stage with Kuon!
You've got the Love Ending!
You've cleared Stage 7 and done an excellent job!
You've cleared the Love Stage with adult Kuon!
You've cleared Stage 6 and done a excellent job!
You've cleared Re-Stage 5 and done a excellent job!
You've cleared Re-Stage 4 and done a excellent job!
You've cleared Re-Stage 3 and done a excellent job!
I remembered all what I've experienced with him.
You've cleared Re-Stage 2 and done a excellent job!
Meet the Great Octopus and fulfill her wish!
You've cleared Re-Stage 1 and done a excellent job!
You've cleared the Re-Prologue!
And now we returned back to the beginning of the game...
You've failed to clear Stage 5, but...?
You've cleared Stage 4 and done an excellent job!
You've cleared Stage 3 and done an excellent job!
You've cleared Stage 2 and done a excellent job!
You've cleared Stage 1 and done an excellent job!
You've cleared the Prologue!