All collectibles - level by level

Table of all collectibles, sorted by level.

Table

Here's the link to the table.
https://docs.google.com/spreadsheets/d/1yNqggnq4fC6fcud6kATpuUjTAP4nmdF4dLT3SUxNsn0
Steam seems to block all google sheets these days, so you may want to copy-paste that link manually. It's just a data table, Steam.

Press "File" -> "Make a copy". Don't ask me for permissions.

Work with your own copy of the table. Every time you collect something, put an "x" (or any character) in the Status column for that item.

FAQ

Q: Are any collectibles missable?
A: Well yes, but no. The diary on level 90 (normal game) seems to be glitchy and missable. However, there are 17 diaries but you only need to collect 16. So it doesn't matter if you get it or not, as the requirement was lowered due to the said glitch. Everything else is not missable.

Q: Will I have to backtrack for collectibles?
A: A few times in the normal game, yeah. Just mark everything you actually collect in the table and come back for the rest later.

Q: Do I have to collect everything before starting New Game+?
A: No, New Game+ is more like a separate gamemode. You can continue normal game and new game+ interchangeably. Your stats and progress transfer across all gamemodes.

Q: How do I use level numbers? The game doesn't display the current level.
A: Unfortunately yes. However, when you click a checkpoint on the map it does display the level number. You can quite easily deduce the numbers of the next adjacent levels. Just remember that shops and boss rooms don't count as "levels", and any optional side paths take priority in numbering (i.e. 70 would split to 71 optional and 72 main).

Q: Why don't you put screenshots of all collectibles?
A: You do it. I'm not playing this god forsaken game again.

Can't find an item? It's in the ceiling!

If you cannot find a certain collectible in a level, then it's in the ceiling.

One orb in normal game and a few more collectibles in new game+ are hidden above the map. Double-check that you're searching the right level first (see above about level numbering). Then look for a clearing in the map's ceiling and jump through it. It's rubbish, I know.

Credits

All data collected from here:
https://callyscaves.com/callys-caves-3-guidesinfo/final-form-collectible-locations/
Then tested in-game.