What is the best way to implement videos in 2D unity game?

Hello, I'm working on a 2D game for IOS and some of the animation i need to implement are very hard to do through unity so I'm importing them. At first i used video player components and mp4 files but it caused a lot of problems so i moved to PNG sequences and a library i found name Playback w$$anonymous$$ch works fine but it makes my game weight a lot (my assets folder is about 120MB but when I'm making a build it weights about 5GB) and it also takes ages to launch unity or moving platform. Any other suggestions or tips or insights about why is it happening or how can i approach t$$anonymous$$s t$$anonymous$$ng? Many thanks.