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