New beta build! https://wiki.arcengames.com/index.php?title=AI_War_2:Multiplayer_Alpha_And_Beta#Beta_2.719_Unity_2019.4.2C_And_Performance
You need to use the current_beta branch on Steam or GOG to play this one. If you have trouble with it, there is a most_recent_stable_beta, now, too.
This one fixes a couple of bugs related to viral shredders, but then beyond that it's all about an upgrade of the unity enginge. It looks like the download size is about 1.6GB at least on OSX, so that's what's up with that -- lots of file format changes in the internal databases.
As part of the upgrade, there were some really notable performance improvements here, most specifically around the drawing of thousands of icons on the galaxy map or planet view. There's more I need to do still relating to the drawing of lines and circles when you have tons of ships selected, but I plan to tackle that tomorrow.
OSX, Windows, and Linux should all see a big surge in compatibility, particularly Vulkan on Linux and Metal on OSX. No native support for the new Mac Silicon chips yet, but unity has that in a beta build and that's probably inevitable in a year or two if they either backport it or get the related version suitably bug-free. This version is a major jump forward in unity build numbers, well over a year, largely because we needed the new version to be rock solid and actually give some tangible benefits. We're finally at that point, knock on wood, so here we are!
Please note the made with unity splash screen is annoying and temporary. It will be gone in tomorrow's release.