Here is the full list of all 30 So Many Me achievements.
Walk around the moon
Kill 10 Cloud-9 soldiers while both 9th Rifle and Helmet are turned on
Acquire 42 costumes
Reach 100% completion
Finish the game
Turn on every light in Chrono Castle
Score 50 or more in Chrono Castle XV
Collect every coin in Chrono Castle
Have 3 different Transmuter Fruits on 3 ME at the same time
Acquire every ME
Unlock both gates at Volcano's entrance
Craft 10 artifacts
Defeat a Duffon
Dream.Build.Play
Score 80 or more in Chrono Castle XIV
Score 550 or more in Chrono Castle XIII
Finish Chrono Castle XII without turning on Etherizer
Finish Chrono Castle XI with both coin bubbles collected
Confront all possible questions in Chrono Castle X and choose all correct answers
Defeat the rival
Have a ninja hanging upside down on a blue fist
Fail your friends
Have 8 ME in 8 different appearances at the same time
In the Chono Castle, Stomp on enemies' head 10 times, without falling down to the ground or creating stone block
Meet Woodword
Enter Chrono Castle
Rescue a girl
Finish any level while riding a Jellosaur
Use the Gene Splicer to create Jellosaur
Acquire the first ME