Here is the full list of all 16 Pineapple on pizza achievements. It takes around 0-1 hour to unlock all of the achievements on Windows.
Activate the volcano.
Approach the kids playing.
Ruin the limbo.
Walk through the corn plantations.
Approach the man feeding the birds.
Approach the skilled dancer.
Approach the turtle.
Step inside the circle.
Approach the statue.
Play.
Get out of the island.
Approach the baby.
Approach the bench.
Step onto a sailboat.
Approach the cliff.
Jump from the cliff.