Here is the full list of all 26 Hitman GO: Definitive Edition achievements. It takes around 8-10 hours to unlock all of the achievements on Windows.
Used a hint, ignored the instructions but finished the level...
Kill 100 enemies using the Silverballers.
Complete all objectives in all chapters without using a single hint.
Complete all objectives in the St. Petersburg Stakeout Chapter.
Complete all objectives in the sixth chapter.
Kill 100 Patrol (Yellow) enemies.
Kill 100 Turning (Teal) enemies.
Get pushed 100 steps.
Crush three enemies under a falling statue.
Play for at least 5,000 turns.
Complete all objectives in the opera chapter.
Kill 100 Pair (Grey) enemies.
Worn all three disguise types.
Complete all objectives in the fourth chapter.
Get chased by three guard dogs simultaneously.
Kill 100 Static (Blue) enemies.
Complete all objectives in the third box.
Killed an enemy by emerging from a Secret Passage.
Complete all objectives in the second box.
Die at least 200 times.
Play for at least 1,000 turns.
Play for at least 100 turns in a single level.
Throw an object without alerting anyone.
Kill 5 enemies at once.
Complete all objectives in the first box.
Killed 2 enemies at once.