Is there way way to go back to previous worlds to get fragments/gold databases I did not get? I beat the game but upon beating it, it said to go get all the fragments/databases to access more.
For now, you would have to have saved the game in earlier levels, and if not, yeah, you'd need to start over.
However, we do plan to have an "auto save by level" feature that will make a separate auto save the first time you enter a level, so you can go back to earlier levels even if you forgot to save.