Here is the full list of all 50 Flood of Light achievements.
Complete RainDay with the 'Sunshine' Ending
Complete task on ground level and gain the S stage glory without replaying
Complete task on 6F level without replaying
Take lights from four different lamp posts
Check out the producer list
Gain a S stage glory on 2F
Gain a S stage glory on 3F
Gain a S stage glory on 4F
Gain a S stage glory on 5F
Complete 100% game progress
Restart the game after completed the Ending
Complete RainDay with the 'Regression' Ending
Gain a S stage glory on Ground Floor
Acquire all Wicks
Collect all 17 letters
Fix Robot Chef
Gain a S stage glory on 1F
Activate the Mountain Prop
Fly and place 20 lanterns
Activate the Water Prop
Extract the power from The Code of Spirit
Activate the Thunder Prop
Complete 50% game progress
Activate the Wind Prop
NEW_ACHIEVEMENT_DESC_1_30
The first time you submerged in water
Extract the power from The Code of Sea
Activate the Fire Prop
Take or move light over 1000 times
Gain a S stage glory on 6F
Take or move light over 666 times
Activate the Marsh Prop
Back to the game again
Take lights from three different lamp posts
Take or move light over 300 times
Check the telescope at Elevator
Fix ALL Robot
Gain a S stage glory on 7F
First time to replay completed chapter
Activate the Land Prop
Complete levels without closing tips
Choose keyboard control on pause page
First time to replay the level
Fix the first Robot you met
Gain a S stage glory on 8F
Activate the Sky Prop
Collect a letter marked 01
Pass through a huge advertisement board on 7F
Take lights from two different lamp posts
Extract the power from The Code of Light