Catherine Cheats

Lord of the Night (10): View the true Cheater ending.
Love is Patient, Love is Kind (10): Resolve Daniel's dilemma.
Making Legends (20): Conquer Stage 8.
Menhir Conquered! (15): Complete Stage 2 of Babel.
Mother Inferior (10): Help Archie work through his quandary.
Nighty Night (10): View the bad Lover ending.
No One Expects the... (10): Conquer Stage 4.
Obelisk Conquered! (20): Complete Stage 3 of Babel.
One Last Case (10): Help Morgan clean up his mess.
Past a Heap of Puzzles (10): Beat Stage 64 of Rapunzel.
Path to the Altar (20): Conquer Stage 7.
Play It Again, Vince... (5): Use the jukebox to change the music.
Push It to the Limit! (10): Push 5 blocks at once. (Golden Playhouse)
Read All About It! (10): Get Justin out of his jam.
Sake Sensei (10): Listen to all the sake sound bites.
Sleepless Nights (10): View the normal Cheater ending.
Starting a New Life (10): View the true Lover ending.
Take Your Time (30): Move a Dark Block 10 times in a row. (Golden Playhouse)
Taking on the Gods (30): Unlock Axis Mundi by earning all Gold Prizes on Normal or Hard.
Text Junkie (20): Reply to at least 20 text messages by the end of the final day.
The Golden Child (100): Earn Gold Prizes on all Hard difficulty stages.
The Great Escape (5): Conquer Stage 2.
The Nightmares Have Just Begun (5): Conquer Stage 1.
True Freedom! (30): Conquer Stage 9.
Welcome to the Colosseum (10): Unlock the Colosseum mode.
What Time is It? (15): Conquer Stage 6.
Whatever, Buddy (10): View the normal Freedom ending.
Whisky Wiseman (10): Listen to all the whisky minutiae.
You Don't Have To Go Home... (5): Stay in the bar until all the other customers leave.

Babel Mode Stages
The Babel Mode lets you take on randomized stages either by yourself or with a friend. You can only unlock these stages by earn Gold Prizes in the Golden Playhouse.

Altar: Earn one Gold Prize from the Golden Playhouse on Normal difficulty or higher.
Axismundi: Earn nine Gold Prizes from the Golden Playhouse on Normal difficulty or higher.
Menhir: Earn three Gold Prizes from the Golden Playhouse on Normal difficulty or higher.
Obelisk: Earn five Gold Prizes from the Golden Playhouse on Normal difficulty or higher.

Stage Skip
Clear all the stages in a chapter with a gold trophy on each stage (consecutively) to get a gold trophy for the chapter. Now, if you replay the chapter, you can press start and skip any of the stages in the chapter, including the boss. This is particularly useful when going for all the endings, especially for the last chapter. Stage skip for a chapter can only be unlocked by getting the gold trophy on Normal difficulty or above. To get a gold trophy on a stage, you generally need to get all the gold coins and have a full step combo from the start of the stage to the end. Step combos don't continue if you die and restart at a checkpoint, so if you are going for a gold trophy and you die, then you need to restart at the beginning of the stage.

Unlock Very Easy Mode
On the title screen hold the back button until you hear a chime. This will activate the very easy mode.

Unlockable
Colosseum Mode: Beat the game once.