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