@xThomas I’m on an iPad 3 which can’t update past iOS 9, and it did work for me, I’ll tell you how.
It’s roundabout but overall I’m really impressed with how careful TwoLivesLeft is to ensure backwards compatibility.
So first you’ve got to get the file into your own Dropbox app on your device, which you can do from Safari. If you don’t have a Dropbox account, that may be a rigmarole, but it’s doable. From that app find the .zip file and tap export. Look for a button that’s like “open in…” or “open in app…”, tap that, an lo and behold there’s an “open in Codea” icon.
After you tap that, Codea will open, and it may take a second or two, but an import window will pop up asking you which files from the zip you want to import. Tap “select all” and it will import all the art, though unfortunately it won’t tell you where it put it, which may be confusing.
It put it in the root Documents folder, and let me know if you don’t know how to get it from there into the a project folder for this project. Once the art is in this project’s Project folder, you’re good to go!