Unasked-for suggestion.
Consider using webp for images and opus for audio, and something like webm for animations in the future. Opus for audio is the easiest swap over mp3, being both higher quality and smaller. webm over animated gifs is also pretty easy, at least the way you're using them for full screen animations. webp probably needs a bit of testing as it has a higher cpu cost, so on the slowest systems could add lag, though the faster load times on rotating disk for the oldest computers might completely erase those costs.
These changes would shrink the 3.3GB current footprint to less than 2GB which would decrease costs for everyone inlcuding you.
Definitely not worth it for this game at this point.