Here is the full list of all 25 Johnny Trigger: Sniper achievements.
Killing by headshot!
Run the hydrant 15 times
Your first death!
Destroy the drone with diamonds!
Destroy 5 cars.
Kill 2 opponents who are in the vehicle!
Change your weapon skin 10 times!
10 games without losing your health!
You have killed the first boss!
You have completed 30 levels!
Upgrade your weapons 5 times!
50 kills with sniper rifle!
You have killed more than 1 enemy at a time!
Destroy 5 helicopters
60 games without losing your health!
You killed the boss 5 times!
You have completed 100 levels!
Upgrade your weapons 20 times!
200 kills with sniper rifle!
Spend 50,000 in cash.
150 games without losing your health!
You killed the boss 15 times!
You have completed 200 levels!
Upgrade your weapons 35 times!
300 kills with sniper rifle!