Here is the full list of all 46 Squids Odyssey achievements.
Use 10 miracle tentacles
Complete all missions in Pro Mode
Level up all squids from to level 25
Level up a squid to level 25
Get 3 stars for all bonus missions
Unlock all seahorses
Complete Chapter 8
Get 3 stars for all story missions
Recruit Oktoku
Complete Chapter 7
Recruit Magnus
Defeat 50 enemies with a jellyfish
Invoke a mighty kraken
Unlock all cursed helmets in your inventory
Unlock all helmets in your inventory
Complete Chapter 6
Recruit Cleef
Complete Chapter 5
Defeat 50 enemies on a Seahorse
Complete Chapter 4
Recruit Brad
Complete Chapter 3
Finish "The Spirit of the West" in 1 turn without inventory items
Recruit Ronimo
Level up all squids to level 10
Defeat 10 enemies in one turn
Hit 6 enemies in one stomp attack
Level up a squid to level 10
Complete Chapter 2
Recruit Calamary Jane
Recruit Jammer
Complete Chapter 1
Beat the first Guardian
Each squid should bounce on something at each turn in mission "Holding Ground"
Defeat 500 enemies
Heal 500 HP with a healer squid
Give a 5 combo melee hit
Recruit Venus
Do 10 combos in mission "The Iron Throne"
Finish mission "back to the wall" in 2 turns
Push an enemy in a hole with a shoot attack in mission "Lady in the Water"
Recruit Vesper
Play a mission with the redemption hat
Recruit Kapono
Recruit Sammo
Recruit Clint