Here is the full list of all 15 Mushroom Men: Truffle Trouble achievements.
Move 10 blocks.
Kill an enemy while being shot out of a cannon block.
Complete a level on Normal or Hard difficulty without falling off the world.
Launch Pax out of a cannon block.
Use a trampoline block.
Complete the tutorial.
Fall off the world ten times in one level.
Speed run of less than 2 minutes on any Garden level.
Jump on a trampoline block 100 times in a row.
Complete a level on Hard difficulty without allowing the princess to get in range of grabbing Pax.
Transform into every one of Pax's forms.
Complete an entire environment on three different difficulty levels. (Bedroom excluded)
After being launched from a cannon block, fly the distance of 1000 blocks.
Kill 50 enemies.
Place a block on top of another block 20 times.