If animations freeze, reducing the number of animations will not solve the issue. You'll just have fewer animations that still keep freezing. Unless you reduce compression or get a better phone, nothing will change.
Frankly, not every phone is suitable as a gaming device. If you decide to save money (or research) and get a potato, you'll have to expect and accept that some games just won't run smoothly. The same goes for PC, by the way: A netbook for example will struggle with most games and compressed video. Make sure to research benchmarks for your next phone, as there are relatively powerful and affordable devices for those who can find them.
The solution I'd suggest on the developer's side is an alternative low-res version with low compression for low-end devices - but that means you're not getting the high-quality animations those with decent phones and computers get.
However, before pestering for alternative versions, have you tried running the PC version under JoiPlay? With JoiPlay, you can play Ren'Py games regardless of size, because the app does not need to contain all the game files like a standalone APK does. PC versions usually have lower compression, which means smoother video playback.
Naturally, PC versions are big. Collecting games with over 10GB will quickly fill up most phones. So if you're running out of space, you can just get a nice terabite-sized external SSD that works with android to keep all your oversized PC versions and APKs. And movies. And Books. And everything.