Fashion Hunter achievement in SpongeBob SquarePants: The Cosmic Shake

There are 35 costumes in the Cosmic Shake.

9 of the costumes are unlocked by playing through the Story, all the other costumes are unlocked via Side Quests & Purchasing them in the Costumes Shop.

You have to collect Gold Doubloons to unlock more costumes in the shop. There are 7 levels, each level requires more Gold Doubloons to collect. You don't have to collect every single Doubloon to get to Level 7. Getting to Level 7 takes 50 Gold Doubloons.

(read edit at bottom of the solution as this changed) Each costume costs 500 Jelly, totaling 12,000 Jelly. I would advise to not spend any Jelly until you have 10,000 Jelly because that's another achievement

The remaining two Costumes are unlocked via Side Quests:

A costume is unlocked via a Side Quest in Halloween Rock Bottom after completing that Level. Details below:

A costume is unlocked via a Side Quest in

after completing the game.

edit: The amount of Jelly needed to get all costumes has been upped, it used to be 500 Jelly per costume.

"It has definitely been updated. Tiers go from tier 2 at 500, tier 3 at 750, tier 4 at 1000, tier 5 at 1250, tier 6 at 1500 and tier 7 at 2000. Confirmed this as of today. Was in the last update." - DoomScott pointed out

It is now 28,000 Jelly to unlock all buyable costumes