Here is the complete list of unlockable achievements for Child of Eden on the Xbox 360. Note that most of them are secret achievements, which I have listed in their own section.
Automaton (5) – Achieved a 4 Star Clear Rank
Dabbler (20) – 10% of Extra bonuses unlocked
Feel The Beat (5) – Achieved a Perfect Octa-Lock
Figure Eight (5) – Purified an enemy using Octa-Lock
Genius Play (20) – Cleared the Matrix Archive on Normal Difficulty Mode and achieved 100% purification
Hot Shot (10) – Achieved a total of 100 Perfect Octa-Locks
Matrix Completionist (5) – Obtained all items in the Matrix Archive
Pulse-Pounding (15) – Obtained more than 800,000 points in the Matrix Archive on Normal Difficulty Mode
The Cleaner (5) – All enemy types purified
The Skills That Pay The Bills (10) – Achieved 10 consecutive Perfect Octa-Locks
The Wireframe Web Expands (30) – Cleared the Matrix Archive on Normal Difficulty Mode
Total Enlightenment (5) – Euphoria used
Ultimate Compiler (50) – Collected all Reward Items in Lumi’s Garden
Here are the thirty six unlockable secret achievements that aren’t listed on the achievements page until you unlock them:
Absolutely Fabulous (50) – Cleared all the Archives on Normal Difficulty Mode and achieved 100% purification
Collector (20) – 25% of Extra bonuses unlocked
Constellation Overdrive (15) – Obtained more than 800,000 points in the Passion Archive on Normal Difficulty Mode
Crackerjack (20) – Cleared the Evolution Archive on Normal Difficulty Mode and achieved 100% purification
Endless Passion (5) – Obtained all items in the Passion Archive
Evolution Pack Rat (5) – Obtained all items in the Evolution Archive
Eye Of The Beholder (5) – Obtained all items in the Beauty Archive
Field Of Dreams (30) – Cleared the Beauty Archive on Normal Difficulty Mode
Fireworks From Heaven (15) – Obtained more than 800,000 points in the Beauty Archive on Hard Difficulty Mode
Flawless Beauty (15) – Obtained more than 800,000 points in the Beauty Archive on Normal Difficulty Mode
Giver Of Life (100) – Cleared the Journey Archive on Normal Difficulty Mode
Gunslinger (15) – Obtained more than 800,000 points in the Journey Archive on Hard Difficulty Mode
Hierophant (20) – Achieved a Gold Star Clear Rank
Hope Springs Eternal (30) – Cleared the Hope Archive
If The Spirit Moves You (30) – Cleared the Passion Archive on Normal Difficulty Mode
Impeccable Virtue (15) – Obtained more than 800,000 points in the Journey Archive on Normal Difficulty Mode
Luminous (20) – Cleared the Passion Archive on Normal Difficulty Mode and achieved 100% purification
Magnificent Aura (15) – Obtained more than 800,000 points in the Evolution Archive on Normal Difficulty Mode
Maniac Play (20) – 75% of Extra bonuses unlocked
Master of Eden (50) – Cleared all Archives with a Gold Star Clear Rank
Matrix Archivist (20) – Cleared the Matrix Archive on Hard Difficulty Mode
Phoenix Rising (30) – Cleared the Evolution Archive on Normal Difficulty Mode
Radiant Avalon (20) – Cleared the Journey Archive on Normal Difficulty Mode and achieved 100% purification
Savant (10) – Achieved a 5 Star Clear Rank
Shimmering Brightness (20) – Cleared the Beauty Archive on Hard Difficulty Mode
SRSBZNS (20) – 50% of Extra bonuses unlocked
Super Collider (20) – 100% of Extra bonuses unlocked
The Great Evolution Round-Up (20) – Cleared the Evolution Archive on Hard Difficulty Mode
The Journey’s End (20) – Cleared the Journey Archive on Hard Difficulty Mode
The Thinker (20) – Cleared the Beauty Archive on Normal Difficulty Mode and achieved 100% purification
The Calculator (15) – Obtained more than 800,000 points in the Evolution Archive on Hard Difficulty Mode
Time Becomes A Loop (15) – Obtained more than 800,000 points in the Matrix Archive on Hard Difficulty Mode
Total Eclipse Of The Heart (50) – Cleared all the Archives on Hard Difficulty Mode and achieved 100% purification
Unforgettable Fire (20) – Cleared the Passion Archive on Hard Difficulty Mode
Wanderer (5) – Obtained all items in the Journey Archive
You Sure Showed Them (15) – Obtained more than 800,000 points in the Passion Archive on Hard Difficulty Mode