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