If I upload the main file, the playdate sideloading interface says there isn't a top-level .pdx file. If I upload the .pdx folder (?), it says wrong filetype. Am I missing something?

I had this problem on my Google Pixel phone as well (uploading the original download to the PD website I mean), I'll try on my computer later today

UPDATE - I got it working, the problem was the zip file contained the file structure Oquonie/Oquonie.pdx/<all the subfolders & files>, but the playdate website expects the Oquonie.pdx to be the root folder inside that zip file (i.e, just Oquonie.pdx/<all the subfolders & files>). Once I zipped up the Oquonie.pdx folder by itself the upload worked no problem

We're glad to hear :) We'll try and get rid of the subfolder in the zip file and upload a new build!