Here is the full list of all 15 100 Pumpkins 2 achievements.
Find 50.
Finish with a completion time of under 25 minutes.
Find and destroy the secret boss.
Find the oldest pumpkin. (doesn't count toward the 100)
Finish the game with more than 10 deaths.
Finish the game with 10 deaths or less.
Complete the map.
Obtain the Double Jump Boots.
Obtain the Running Boots.
Obtain the map.
Destroy the snake boss.
Destroy the spider boss.
Destroy the final boss.
Unlock fast travel.
Obtain the pitchfork.