Here is the full list of all 33 Giraffe and Annika achievements.
Unlocked all achievements
Cleared all rhythm games on all difficulties at A rank or higher
Cleared every rhythm game with no misses
Obtained all bonus drawings from rhythm games
Beat the game within 4.5 hours
See every conversation with Mrs. Save
Obtained 3 bonus drawings from rhythm games
Cleared every hard rhythm game on S rank
Received a Christmas gift
Cleared dungeon 5
Cleared every rhythm game at normal or higher
Cleared all rhythm games on hard mode
Collected all meowsterpieces
Hit every drum
Stuck your face into every photo stand-in
Got 'Great Fortune' result on my fortune
Cleared dungeon 4
Delivered something Giraffe forgot
Changed into the swimsuit
Collected every mysterious paper scrap
Collected 24 meowsterpieces
Ate 50 foods
Cleared the Fire Dungeon
Collected 18 meowsterpieces
Collected 12 meowsterpieces
Saw the special idle animation
Collected 6 meowsterpieces
Went into the bathroom 5 times
Took 50 or more photos
Cleared the Ocean Dungeon
Cleared the forest Dungeon
Obtained the bag
Obtained the key to Lisa's house