I did a run off of a camera, as I'm curious as to what the rules are when a camera-recorded run gets checked for approval. Are there any rules for this or not?

If it's watchable it's fine. There are a few checks we make to check a camera run is up to verification including checking for consistent bolt and health counts.

So that means if the camera doesn't show the HUD (Bolts, Health, Ammo) during a run, will it be invalidated?

Yes, fortunately it's not hard to do.

Oh I see.
And there goes my recorded run LUL

Do another one lol