Oh, I mean on the audio waves timing/animation: add around 1 or 2 frames of animation right before they flare up or got down, that way player can be a bit cautious on when to time passing through. The way it is now is okay in timing wise, but small visual animation cue can help player to get ready to make the jump more managable ;)
On the save, it's okay. It's small things hahaha. Consider checkpoint placements if you plan to update this game after the jam. But even as it is now, it's already a pretty solid game! Good job!
I think the visual are very well done in both 3D and 2D, it's astounding work!