Whilst most Menu Background Animations work for 32:9 (5120x1440 specifically), I've noticed two that don't:
The one where the engineer chases a single alien from left to right off screen, just to return a second later and be chased by a lot of aliens.
On 32:9 the animation starts on the screen rather then off screen and you can see where new aliens are spawned in and it also ends prematurely:
The other one is where a line of tanks bulldozes over some alien nests.
On 32:9 you can see some of them crash into a cliff, which is probably not intended:
[1.1.101] Menu Backgrounds not widescreen compatible
Re: [1.1.101] Menu Backgrounds not widescreen compatible
Thanks for the report however I don’t consider this worth changing.
If you want to get ahold of me I'm almost always on Discord.