Hi guys !
For this achievement you need to collect all 161 Butterflies in the game.
Here's my full 100% Walkthrough with timestamps (below each video,in the Spoiler part) to get all of them :)I'm sorry for the poor quality of my video at some moments.My connection isn't great at the moment due to the bad weather.I wanted to create the perfect guide for Projection but my connection isn't argee haha.Hope it still helps !
If you missed some butterflies, you can still get them in Chapter select.
But careful, you need to collect ALL butterflies in the level to get the 100% on it (the new butterflies and those already collected).Chapter 1-5:
And that's done ! Congratulations and enjoy your 100% ! :D