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