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.
Kill 100 Pair (Grey) enemies.
Kill 100 enemies using the Silverballers.
Used a hint, ignored the instructions but finished the level...
Complete all objectives in all chapters without using a single hint.
Complete all objectives in the sixth chapter.
Complete all objectives in the St. Petersburg Stakeout Chapter.
Complete all objectives in the opera chapter.
Kill 100 Turning (Teal) enemies.
Complete all objectives in the fourth chapter.
Die at least 200 times.
Crush three enemies under a falling statue.
Get pushed 100 steps.
Kill 100 Patrol (Yellow) enemies.
Get chased by three guard dogs simultaneously.
Play for at least 100 turns in a single level.
Kill 5 enemies at once.
Complete all objectives in the third box.
Play for at least 5,000 turns.
Kill 100 Static (Blue) enemies.
Complete all objectives in the second box.
Worn all three disguise types.
Complete all objectives in the first box.
Killed an enemy by emerging from a Secret Passage.
Play for at least 1,000 turns.
Throw an object without alerting anyone.
Killed 2 enemies at once.