Maybe I could help you on this. What linux distro did you use to test your game? Is the animation did use any special video format or is it some kind of video playback within the game engine itself? There could be a missing packaged from your distribution that could cause the animation to failed to play. I don't know what is the game engine you are using but is there any debug tool that can you tell more when the animation failed to display?
Viewing post in Project Realism v0.2.0 [PATREON EARLY ACCESS] comments
I use Mint to test the version, though I've had someone else test it and they were on Ubuntu. It fails regardless of installing media packages like gstreamer.
If you wish to know the technical reasons, the framework I use serves assets on a custom protocol. The game runs on web views and on Linux this is webkit2gtk. Recently (several months ago by now), this web view released an update that broke mp4s served on that custom protocol. I'm not sure why or what happens but it is a known issue.
If you can, send me a message on Discord and I might be able to send you a build for you to test.
I'm using Debian sid from my end. I did use Mint and Ubuntu in the past but had many issue due to some outdated package so I always go back to Debian sid since it fit more my need.
I don't have much time this week but on next week-end I should be have some free time to look at it. I will contact you over Discord.