Here is the full list of all 10 Snake-a-roni achievements.
Spend 5 minutes in menus
Spend 10 minutes in menus
Spend 1 hour playing
Eat to 1000 length
Reach the 3rd stage in Adventure mode
Have 10 Adventures
Have 10 Snake fights
Unlock 20 Hats
Unlock 25 Hats
Watch the Credits to the End