Here is the full list of all 48 The Adventure of NAYU achievements. It takes around 0-1 hour to unlock all of the achievements on Windows.
Knock down 3 GuBee's kings.
Visit 50 areas.
Collect 47 achievement stamps.
Defeat the GuBee's King.
Unlock 35 items from Lugh's information shop.
Release the witch's outfit.
Release the ninja outfit.
Release the spearman outfit.
Release all outfits.
Unlock 21 items from Lugh's information shop.
Maximum damage exceeds 99999.
Knock down 20 boss-level monsters.
Activate the game for 60 minutes.
Increase the adventurer level to 300.
Visit 25 areas.
Increase the adventurer level to 200.
Maximum damage exceeds 9999.
Unlock 7 items from Lugh's information shop.
Go into fever mode 10 times.
Collect 50 pieces of cheese.
Release the cook's outfit.
Knock down 100 monsters.
Collect a cumulative total of 100000 shards of stars.
Increase the adventurer level to 100.
Start endless mode
Collect 23 achievement stamps.
Update your high score on the Road to Cheese.
Collect 10 pieces of cheese.
Collect 30 pieces of cheese.
Complete the story
Activate the game for 30 minutes.
Release the guardians of the Forgotten metropolis.
Informed Shiro what you want.
Discovering the Forgotten Forgotten capital.
Collect a cumulative total of 10000 shards of stars.
Defeat the cave boss.
Encounter the researcher in the cave.
Knock down 50 monsters.
Out of the woods.
Activate the game for 15 minutes.
Strike 300 times.
Meet Suzu and become friends.
Defeat Rye in the woods.
Defeat Lev in the woods.
Clear the first area of the story.
Defeat the bear in the meadow.
First time in fever state.
Got your first shards of the star.