Despite its linear structure, FF7 Remake has some hidden secrets and collectibles. One of them is the music collection - albums scattered throughout the game. Another thing that can be missed is odd jobs - side missions that we can complete every now and then. Can you go back to them after the game is over? What about the missed collectibles?
Yes, you can go back to the elements you missed after beating the game. Once you have completed all the chapters, you will unlock the option to replay any of the chapters - you can play it all over again with your current equipment and abilities. This way, you can go back to the things you left out for later/missed.
What is more, the game in a way requires you to go back to certain parts. To complete the game in 100%, you must e.g. go back to Chapters 3 and 8 to complete side missions in different ways (skip some of them, complete them all, etc.) to get other outfits for Aerith and Tifa during Chapter 9 and complete other side missions in this chapter.