So I got some more feedback on how to improve the usability.

I've had at least two people complain that they couldn't pick up any items, but didn't specify if this was before or after picking up the coat. Unfortunately, I haven't been able to reproduce this, so if this is happening after getting the coat, that would be a problem. If it was before, I think users would be less likely to give up if I placed the first letter in plain sight closer to the coat so the time between them trying it and giving up is less.

The other thing is that some people don't like the default keyboard controls, so I've adapted them to make them more like the ones a lot of platformer games on itch use - x and z for jump and interact and I'll move the item toggle buttons up to a and s. Configuring new inputs also didn't seem very intuitive, so now it displays the older inputs for reference.

I got some feedback that people thought all the words that show up in the map are doors, when there are some levels where you will find letters, but are actually dead ends, but the UI doesn't make that obvious, so now the icons change to reflect that. 

I've been trying to see what exactly about the platforming is causing issues again, from what feedback I already have, and I think the only other thing was the ledge climbing. It's not obvious in all levels; just some of them. Apparently, mapping hanging on ledges with the arrow buttons wasn't a good idea because the arrow buttons are involved with jump control, and trying to control jumps while sometimes not wanting to hang onto a ledge gets in the way of that, so now I've changed ledge climbing to rely on the jump button instead. I don't know if this will be better overall, or just fix this one problem with the sensitive ledges, but I hope it will make the game more playable for the people that didn't like it.