First of all, I want to say that I received my Playdate today and it is already exceeding my expectations in every way!
I am sideloading a couple of games I've found on itch and most have worked without issue through the web UI, except for a couple of prototypes and this released game: Yoshimi Yahtzee by Yoshimi Games
In each instance the zipped pdx uploads for a moment and then spits back this image:
The pdxinfo file inside the game bundle doesn't appear to have a bundleID field. The author of the game will need to add one for distribution to work correctly. This is explained under Game metadata in the docs.
I see no reason that wouldn't work, but if you later install a new version of the game under a different bundle ID it won't be able to access your save files, and if the game uploads high scores, that won't work either. So the best solution is to wait for the author to choose a unique ID for the game.
Fair enough. I am hoping to provide some feedback since I got the device in hand, so my high score in Yahtzee can take a bullet in this event! Thanks again, Dan!
That would work (assuming you mean io.itch.therussianbeargame.pop-pop or similar).
Using a domain or subdomain that you control is an informal way of guaranteeing uniqueness across games and developers; there's no technical reason for it. (Spelling it in reverse is sort of a historical artifact.)