Datasets:
About the metadata
It has issues with submissions like https://opengameart.org/content/dungeon-crawl-32x32-tiles
Your data says: author=MedicineStorm
Website: Chris Hamons (maintainer) (Submitted by MedicineStorm)
For the files column it would probably be helpful to ls or tree the conent of the archives and file for files. The images come in various dimension, which you can’t tell by the file size alone. 8-bit colormapped PNG produces smaller file sizes than RBG. Dimensions can be interesting to see how much there is in the submission. Some artists undersell their submissions with the titles, descriptions and previews they choose. (like https://opengameart.org/content/dead-gunner)
Though dimension itself doesn’t tell that much as well since they can contain previews, duplicate tiles, recolored tiles…
EDIT: It also does not contain amount of favorites and "Copyright/Attribution Notice" section of some submissions like https://opengameart.org/content/zoria-cc0-pack
EDIT2: https://opengameart.org/content/great-burst-set is listed with "size": null for some reason