Here is the full list of all 57 Taco Gun achievements.
Land 20 Headshots
Land 100 Headshots
Land 1000 Headshots
Kill 100 Enemies with Avocado
Kill 100 Enemies with Chilli
Kill 100 Enemies with Maiz
Kill 100 Enemies with Arandano
Kill 100 Enemies with Coco
Kill 100 Enemies with Choco
Kill 100 Enemies with Phantasma
Kill 1000 Enemies with Avocado
Kill 1000 Enemies with Chilli
Kill 1000 Enemies with Maiz
Kill 1000 Enemies with Arandano
Kill 1000 Enemies with Coco
Kill 1000 Enemies with Choco
Kill 1000 Enemies with Phantasma
Kill 10 Enemies with Ricochot
Kill 10 Enemies with Multishot
Kill 10 Enemies with Bombshot
Kill 10 Enemies with Powershot
Kill 10 Enemies with Clustershot
Kill 10 Enemies with Choco Knife
Kill 10 Enemies with Pepperang
Kill 100 Enemies with Ricochot
Kill 100 Enemies with Multishot
Kill 100 Enemies with Bombshot
Kill 100 Enemies with Powershot
Kill 100 Enemies with Clustershot
Kill 100 Enemies with Choco Knife
Kill 100 Enemies with Pepperang
Kill 10 Enemies with Avocado Mine
Kill 10 Enemies with Molotacov
Kill 10 Enemies with Bazooka Corn
Hit 10 Enemies with Blue Ooze Jam
Kill 10 Enemies with Coconut Bomb
Kill 10 Enemies with Lock'n'Load
Kill 10 Enemies with Ghost Pepper
Kill 100 Enemies with Avocado Mine
Kill 100 Enemies with Molotacov
Kill 100 Enemies with Bazooka Corn
Hit 100 Enemies with Blue Ooze Jam
Kill 100 Enemies with Coconut Bomb
Kill 100 Enemies with Lock'n'Load
Kill 100 Enemies with Ghost Pepper
Pierce two enemies with a single Powershot
Pierce three enemies with a single Powershot
Make the Conveyor belt in Factory reach maximum speed
Kill an enemy while your butt is on fire in the Kitchen
Consecutively throw 2 enemies off the Boat
Consecutively throw 3 enemies off the Boat
Be very very sneaky on the Train
Get thrown off the Train by obstacles 5 times in a single match
Survive the train in the Canyon by jumping over it
Kill 5 enemies whilst riding a meteor in Space
Have 5 enemies drown in lava sauce in the Volcano
Die to the flying toilets in UFO 3 times in the same match