Here is the full list of all 56 Little Walker achievements.
Beat the game on either mode
Unlock 7 blocks
Felt the mighty power of the monoforce
Rode the golden dragon
Walked on the rainbow bridge
Jump 1000 times
Straight up murdered a majestic creature of the sky
Ate one of those red berries
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)
Meet the moleman
Straight up murder Carl
Disturb the penguins
Talk to the funky seagull
HAPPY FEET, THAT AIN'T FALCO
Hi again!
Pick up the rock
Squish the fly
I get knocked down! but I get up again!
Fail to get back up
Flipped the day/night switch
Myup that was dookie
I hope you're proud of yourself
Level up
Went to the bathroom maybe?
Get a plusm
Get spoken to by any character
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
Kick a dude in the head
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
Read the sign you shouldn't have
Beat the game on auto-walk mode
Did the training room
Found moon mode... Oi.
Found a shortcut
Discover the weirdos
Found the legendary baby coin
Beat the game without hitting 0 hp
Discover that one place
Beat hard mode!