Well, the endgame and post meteor impact is developable. Some days ago i wrote an idea of how it could be more challenging without to be unfair. Maybe you give it a try. Any feedback welcome ;-)

http://ecoforum.strangeloopgames.com/topic/4567/setable-meteor-diameter-to-change-level-of-difficulty-pre-post-impact-challenges

I like your ideas. Especially that animals should have something like a blood trails for better tracking after being shot. That fish is kinda useless isn't first time i read it here.