Hello, first off amazing game. I can honestly say it's one of my favorites to play.
As far as suggestions I do have a few ideas from my time playing. I do understand that not everyone will agree and that's okay they are just ideas.
Tame various bugs. Each tameable bug has different strengths. Ants could scavenge supplies for you, perhaps you could fly around on a bee, etc.
Have various loadouts you can switch between as long as you have the proper gear in your inventory. This loadouts would switch your mutations, armor and trinkets around.
Upgradeable backpack
As far as another boss, perhaps a tarantula that was a pet of one of the kids, and somehow it's cage got knocked out of the bedroom window or something and it got loose in the yard.
Personally I feel the crow should be more of a threat to the player.
Weather would add an interesting mechanic to the game
An upgradeable glider that works like the dandelion tuff
Thank you for reading. I am sure I will think of more as time goes on but for now I will call it good.