Here is the full list of all 56 Little Walker achievements.
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
Jump 1000 times
Flipped the day/night switch
Dancing in the desert blowing up the sunshine
Conquered the cliff
Touched the apple wife (sadly she had apple-butt)
Kick a dude in the head
Straight up murder Carl
Disturb the penguins
Talk to the funky seagull
Ate one of those red berries
Hi again!
Pick up the rock
Level up
I hope you're proud of yourself
Myup that was dookie
Get a plusm
Did the training room
Get spoken to by any character
Fail to get back up
I get knocked down! but I get up again!
Went to the bathroom maybe?
Get an achievement
Defeat 100 enemies
Ate the trashcan sandwhich
Get 64 plusms
Use the air breaks
Ran on hot coals for a while
Walk 500 miles
Walk 500 more
Squish the fly
Meet the moleman
Pop 99 balloons
Discovered the desert birds burrow
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
Found moon mode... Oi.
HAPPY FEET, THAT AIN'T FALCO
Found a shortcut
Unlock 7 blocks
Discover the weirdos
Found the legendary baby coin
Beat the game without hitting 0 hp
Discover that one place
Beat hard mode!