Itchio Downloader Tool
Install
pip install git+https://github.com/emersont1/itchio
Download All Games in library from account
python -m itchio.downloader
This uses the same API the itchio app uses to download the files. If you have 2FA enabled, generate an API key here and run the following instead
python -m itchio.downloader --api-key=KEYHERE
Add All Games in a bundle to your library
python -m itchio.downloader
This is a bit of a bodge, but it works. It essentially goes through and clicks the "Download" link on every item on the bundle's page, which adds it to your itchio library. It does not download any files. You will need the download page's URL (this will be in the bundle's email, and possibly your purchase history). It will not work with 2FA, and I'm unlikely to be able to fix it without making it far more complicated