Yes, you can automate with scripts the "right-click and download image" for complete collections.
Note: For let's say a 9 900 artworks collection it's not instantaneous and be fair with your request and add a minimum 0.5sec or more wait delay / throttle since, yes, the script will run for hours e.g. let's assume one request/per second and a collection with 9 990 artworks, that is, about 9 900 seconds for 9 900 requests (if you assume a non-blocking fast response) and 9 900 seconds - that is about 60 minutes x 60 seconds equals 3600 seconds thus, about three hours.
If you now download in step two the images that's another three hours and so on.
As an example let's redo the 24px collection (that is, the first 24px collection - 24px Cool Cats).
Step 1 - Download all meta data files (in JSON) for the complete collection via the OpenSea HTTP API
Step 2 - Download all "hi-res" images for the complete collection using the image reference in the downloaded meta data (from step 1)
Step 3 - "Pixelate" all "hi-res" images down to the original resolution (e.g. 24x24 or 28x28) and try to change the background color to transparent
See 24px/pixelate
Step 4 - Profit! Generate the All-In-One Composite Image from the "Pixelated" Originals (from step 3)
See 24px/composite
Bonus - Step 5 - Generate a Attribute Dataset in the Comma-Separated Values (CSV) Tabular Format from the JSON Meta Datasets (in step 1)
See 24px/attributes
That's it for now.
See the Awesome 24px (and 28px¹) Downloads page for free ready-to-download pixel art collections in the 24x24 (and 28x28¹) format.
¹: Note - The bored apes from the weape24 series are in the original 24x24 28x28 format.
Post them on the CryptoPunksDev reddit. Thanks.