Your images are in PNG format, if you convert them to WEBP format instead you'll save a lot of space - images will go from 1.5-4 MB down to 0.1-0.3 MB or less, and that will drop the size by quite a bit.I thought about these animation sequences but bruh I have only 8 animations and it's already almost 600 Mo, imagine having a 10 gigabytes game as we reach v0.4 .
For instance - I converted some of Anna's images, and they went from 1.1-2 MB down to 11-108 KB, which is a vast reduction in size. The 20 files I tried this on as PNG takes 27.1 MB, meanwhile when converted to WEBP the same files only take 1.24 MB - that's a 21.8 times reduction in size.
I have no idea how to do it, but you might also want to look at how to compress the video's for the animations as well. Some of them are ok sized at 3-4 MB... but 60 MB for a video of a kitchen sink?
Note: I have no clue how to do this. I just used an online converter, which only gave 20 free converts. However if you have a program such as Photoshop or equivalent, you can prolly do this - and apparently there is also browser extensions that can do this as well. Just wanted to bring this up, esp if you're concerned about the size of the game.