Here is the full list of all 56 Little Walker achievements.
Conquered the cliff
Touched the apple wife (sadly she had apple-butt)
Straight up murder Carl
Disturb the penguins
Use the air breaks
Talk to the funky seagull
HAPPY FEET, THAT AIN'T FALCO
Discover that one place
Hi again!
Pick up the rock
Ate one of those red berries
Squish the fly
Level up
I get knocked down! but I get up again!
I hope you're proud of yourself
Myup that was dookie
Get spoken to by any character
Get a plusm
Went to the bathroom maybe?
Get an achievement
Fail to get back up
Defeat 100 enemies
Ate the trashcan sandwhich
Get 64 plusms
Flipped the day/night switch
Ran on hot coals for a while
Walk 500 miles
Walk 500 more
Jump 1000 times
Meet the moleman
Kick a dude in the head
Pop 99 balloons
Dancing in the desert blowing up the sunshine
Discovered the desert birds burrow
Enter the pyramid
Ring the bell above the abandoned mission
Drank the very last swig that was just sittin there
Straight up murdered a majestic creature of the sky
Found spocker
You just have to keep eating food that's been sitting around, don't you?
Straight up robbed some dudes tomb
Found the invisible block
Walked on the rainbow bridge
Rode the golden dragon
Felt the mighty power of the monoforce
Read the sign you shouldn't have
Beat the game on either mode
Beat the game on auto-walk mode
Did the training room
Found moon mode... Oi.
Found a shortcut
Unlock 7 blocks
Discover the weirdos
Found the legendary baby coin
Beat the game without hitting 0 hp
Beat hard mode!