If you're looking to unlock all there is to unlock in Sackboy: A Big Adventure, then you're going to need to get your hands on a large sum of Collectabells. Having enough of the in-game currency in your wallet will, of course, open up new items and costumes for you to purchase at Zom Zom's Shop, which can be accessed between World Maps and optional levels.
Earning Collectabells doesn't come easy, though, as you'll soon come to learn as you begin your epic quest through the World Maps with Sackboy and friends. But to put so much as a dent in Zom Zom's stock, you will need to onboard these nifty tips the next time you embark on one of the game's many, many adventures.
Complete Levels With A High Score
The easiest and most efficient way to earn Collectabells is to complete the levels with a high score. Seeing as each level is rounded off with a Bronze, Silver, or Gold rating, you will need to aim for a higher rank in order to accrue more Collectabells.
That said, there is a slight chance that earning a Gold ranking will net you an award, as opposed to a set amount of Collectabells. If this is the case, then you can replay the level to essentially whittle down your score for another shot at bagging more of the in-game currency.
Open Crates And Pumpkins
Another effective way to round up Collectabells is to crack open the crates and pumpkins that are scattered around the World Hubs. Also, Collectabells have a tendency to show up near Score Bubbles, which can also be found scattered around the levels. Acquiring any of these during the level you're working through will automatically boost your overall Collectabell currency.
Play Mini Games
A third way to earn Collectabells is through Zom Zom, the Costume merchant who occasionally offers you the chance to play a mini-game or two. By accepting these offers and completing the short activities, you will essentially earn a few more Bells for your wallet, which can then be exchanged for items at Zom Zom's Shop.
Replay Tougher Levels
In short, you will earn the Collectabells needed to purchase all 300 Costumes just by replaying the levels several times over. Having said that, the tougher levels do tend to have the higher payouts, therefore you should aim to play the later stages as much as possible. If you can clear the final stages of each world as well as the boss levels, then you will eventually earn enough Collectabells to clean house at Zom Zom's Shop.