Here is the full list of all 28 Trine 3: The Artifacts of Power achievements. It takes around 6-8 hours to unlock all of the achievements on Windows.
Beat the final boss
Collect each Trineangle from every Chapter
Complete all of the main story Chapters
Earn every Achievement in Trine 3: The Artifacts of Power
Collect each Trineangle from the Chapter: "The Redwood Forest"
Complete the Chapter: "The Redwood Forest"
Survive through the Chapter: "A Dangerous Outing"
Survive through the Chapter: "A Whisper of Evil"
Collect each Trineangle from the Chapter: "The Chronicles of the Guardian"
Complete the Chapter: "The Chronicles of the Guardian"
Complete the Chapter: "A Wizard's Epiphany"
Complete the Chapter: "A Wizard's Nightmare"
Complete the Chapter: "The Astral Academy"
Collect each Trineangle from the Chapter: "The Astral Academy"
Complete the Chapter: "A Brush with Death"
Survive through the Chapter: "An Academic Invasion"
Complete the Chapter: "A Lonely Knight"
Complete the Chapter "Academy Outskirts"
Collect each Trineangle from the Chapter: "Academy Outskirts"
Complete the Chapter: "A Forgotten Parchment"
Survive through the Chapter: "A Squabble in the Jungle"
Complete the Chapter: "A Tumble Down"
Complete the Chapter: "The Three Heroes - Amadeus"
Collect each Trineangle from the Chapter: "The Three Heroes - Amadeus"
Complete the Chapter: "The Three Heroes - Zoya"
Collect each Trineangle from the Chapter: "The Three Heroes - Zoya"
Complete the Chapter: "The Three Heroes - Pontius"
Collect each Trineangle from the Chapter: "The Three Heroes - Pontius"