UPDATE: After observing many people trying to play the game but either quickly losing interest in trying to find all 500 coins or having trouble to the point where they needed to look up my walkthrough to find the remaining ones, I decided to edit the required coins from 500 to 100 in order to beat the demo.
All 500 coins are still in the game in the same places, but it's no longer required to get 100% of them. You are still free to try finding them all though!