So... I thought you had to get all the animals at once and I managed to beat the first few levels and then started banging my head against this game because it was so hard. Then I realized you could do one at a time... lol.
Also the moment I beat the first level - I thought that was going to be it, as it was quite difficult, and then I saw the whole skill tree! What a surprise.
You really put a lot into the game. Awesome job.