Thanks for your suggestions! I already heard from another player that it might be interesting to have some option to deal with parasites and tumors in a "less manual" manner. So I will definitely add your suggestion to my list.
The game still might need a few balance and content patches since I am not fully happy with a few things. Mainly, lungs - they might be the least required organ and they don't really synergize with other game mechanics through evolution upgrades (like, for example, eyes and ears do by improving other organs damage output after certain evolutions).
The needler organ does have a few evolutions that improve it. Lowering the minimal range, improving turning speed and fire rate, improving projectile speed, knockback, damage, and stun chance. But maybe I made a default unupgraded needler "too restrained" in the process of adding all those evolutions...