Just collect coins. You have to make your character hover over the items in the shop to buy them. Press "C" to change the costume. Click on the arrow in the top right corner to open your inventory. Click on the edge of the inventory to close it. This project has 880+ blocks of code.
I used some royalty-free sound effects from the internet. In terms of likes and favorites, this is my most popular project. This is supposed to be an improvement on this project: https://scratch.mit.edu/projects/441818113/
