Here is the full list of all 12 Train Bandit achievements.
Kill 99 snakes
Kill Poncho quickly
Unlock Box Cat
Kill 2000 enemies
Kill three different sheriffs in a game
Unlock E. Lawphant
Unlock Bright Bandit
Shoot 1000 bullets
Die 1000 times
Unlock Flap
Unlock Doughnut
Unlock every bandit