itch.io

You get a little tick mark on the world map and on the actual route generators themselves if you are missing most of the key items / friends. This really helps with progression. But for 100% stuff like tapes you're on your own. The map will mark any thing you see but haven't yet collected, and if you have explored the entire map or not. So in my experience you can get almost everything through brute force, but not easily 100%.