Just started playing the game a few days ago and wanted to share some ideas I had, my apologies if any of these have already been discussed ad nauseam.
First, I love the idea of the Koi fish being an apex predator in its pond and I'd like to see one or two more around the world that you just have to avoid. It would add a bigger sense of danger to the game. To add some counter play, maybe have some armor sets provide a camouflage bonus (i.e. the clover armor provides camouflage in grassy areas, making it harder for predators to notice you instead the current bonus).
Secondly, I think some of the bugs that are currently aggressive shouldn't be, or at least not at the point they are now. The vast majority of stink bugs are herbivores and mosquitoes eat nectar (only the females bite for blood, which you wouldn't be a good source of, given your size). Wasps or dragonflies would be great additions if you want to keep the number of aggressive bugs up. Given the size of the characters, I would also expect Ladybugs to want to hunt the character for food since you are only slightly larger than an aphid.
As far as the survival part of the game goes, I also feel like not enough water is required (does this change with higher difficulty settings?). I often times forget that it is even required and when the game gives me a warning I track some water and some snacks down and get back to it. I also don't feel like the game feels dangerous enough at night, it just gets dark. I have found myself out multiple times and when it's dark I just run back or build a quick lean-to. Have I just been lucky that I haven't run into a roaming wolf spider or do they not really roam that far? Maybe I'm the only one that wants survival to be a bit harder and if that's the case, the game is still plenty fun. I assumed the difficulty settings just make combat harder, which is usually the case.