Hi, you need to download the game from here directly, the desktop app of Itch doesn't support VoidBound as it is too big in file size.
So once you downloaded it either over mega or google drive, simply extract the game using winrar or 7zip and then start it over the game.exe.
Let me know if that helps.
If you need more assistance, feel free to join our discord and tag @crew on there as can help you out more directly.
Best Regards