For the record, I tested the Linux build and it has the same issue as the Windows build.
When building with Godot for Windows or Linux (and not using C# / Mono), there will usually be two output files: an engine EXE and a game assets PCK. You either need to ZIP them together into a single upload, or use the "Embed Pck" option in the Export window to have the engine merge the files for you.
Yeah, unfortunately it appears that the game is unplayable. As far as I can tell, nothing uploaded is actually specific to the game (just stuff from the Godot engine), so there's nothing that can be done to get it to play as-is.
Since the ability to edit uploads during the rating period is disabled by the jam, there isn't really a way to fix it. There's only <12 hours left to the rating period, though, after which you will be able to fix the upload at least.
