Notable entries:

• Make Visual Novels! Ren’Py Transition Kit
• Immersive Particle VFX for Ren’Py
• Voice acting asset pack

I also contributed to the jam myself together with a friend with a collection of 15 simple decorative frames (both as transparent PNGs and ready-to-use Frames for Ren’Py)

Many of the GUI packs are only free for a limited time, so I would grab them before the end of the month!