What external assets did you use in this jam?
I started the jam out with a project that had the VR controller I ended up with at the end of my last VR game jam (Valem's), which is a lightly modified VRIF controller. Here's a full list of the Unity assets I used or had in the project intending to use (mostly editor tools):

Editor Tools: VRIF (BNG Framework), EasyColliderEditor, Ludiq Peek, MMFeedbacks/MMTools by MoreMountains, Sirenix Odin Inspector, Pixelplacement Surge (for Tweening and State Machines), Probuilder, TextMesh Pro, Fullscreen, MaterialOverrides (from the Unity FPSSample)

Particle Effects: FX Fire Free (just a gag joke)
Outlines (not even sure which one I'm actually using): AdultLink Rimlight, HighlightPlus, OutlineEffect by José Guerreiro, QuickOutline by Chris Nolet

I also used a few CC0 sounds from freesound.org; just a few CC0 meshes from TurboSquid and cgaxis.com. I also used quite a few sounds from the free Oculus Audio Pack.

What was your favorite part of this jam?
Probably finding cool audio to use in the game was my favorite this time around.

What was the hardest part of this jam for you?
To be honest it was a slog all the way through due to life sucking time away and hard-to-debug issues. Waiting for a build sucks. And not being able to figure out how to test a lot of things outside-of-VR (I used an emulator but it can only do so much. You really have to jump into it in VR to test physics, scale issues, etc). Unity only crashed on me twice, which is actually WAY less than normal, so that was nice.

What resources/tutorials do you wish you had when making this game?
Unity physics always gets weird when rigidbody/colliders are not at 1:1:1 scale. I have some editor tools to help, but I still end up with wonky physics a lot in VR. I guess tips and tricks and tools on solving these weird issues would be cool.