Here is the full list of all 28 Stick Fight: The Game achievements. It takes around 8-10 hours to unlock all of the achievements on Windows.
77 sniper kills
All other achievements
Win on a match where a black hole appears
Kill 3 other players within a short amount of time
Win a round by killing 3 opponents using the blink dagger
Kill 3 other players in one round
kill 3 other players in one round without taking damage
Kill 2 other players within a short amount of time
Finish a round on each map of the game
Win on every level
Win by reflecting a bullet with the block
Pick up a Light-sabre
Win the round after all ice is destroyed on an ice-level
99 total kills
Block your opponent then immediately kill them with fists
Kill an opponent with the last bounce of the bullet of the bounce weapon
Kill 10 in a row without dying
Kill 9 in a row without dying
Kill 8 in a row without dying
Kill 7 in a row without dying
Kill 6 in a row without dying
Kill 5 in a row without dying
Kill 4 in a row without dying
Win a round by every opponent falling off the map
Headshot
Get killed by a snake
Become the target of a snake and survive the round
Kill an opponent with a mid air kick