Thanks for the tip, I did some research. H264 is the most common format and the one recommended by Unity. It’s the format that consumes the least and hence lags the least. According to Unity, VP8 has indeed better cross-platform support, but it doesn’t have hardware acceleration on old Android devices so they won’t have the power to decode 720p video anyway. On Windows, I think not being able to play H264 videos means something is missing on the computer. On Linux, my games don’t even launch anymore since I updated to Unity 6.2, so I don’t need to be compatible with them I guess.