Here is the full list of all 30 Porcunipine achievements.
Collect a total of 666 skulls in the practice mode
Earn every achievement in the game
Kill 5 or more enemies with a single shot
Kill the fastest wolverine
Reach 48 hours of play time
Get stoned by a falling boulder at 4:20 pm
Kill a player 10 times by bouncing a shot off a rock
Win a Last Man Standing game without ever breaking your helmet
Finish an entire Last Man Standing game without dying
Win a round of Last Man Standing without killing anyone
Make a 3 players combo kill in Last Man Standing and win the round
Visit every arena in the game
Activate switches 100 times in a round
Collect 500 skulls playing for team Red
Die inside the Pyramid
Collect 500 skulls playing for team Blue
Stand in the snow area for 15 seconds straight in the Ice Age level
Kill the Blue porcunipine 100 times
Win a team game without ever killing your teammates
Win a game against a team of 3
Play as Blue porcunipine in Team Red or as Red porcunipine in Team Blue
Win an Arena game with at least 10 skulls more than the other players
Play with 3 friends
Kill all 4 players (yes, including yourself) with a single shot
Play one minute in the Arena mode without collecting any skulls and dying
Stand still for 15 seconds
Play practice mode as every porcunipine
Win an Arena game against 3 bots
Kill a player while dead
Make 2 close calls on different players with a single shot