I think this game perfectly the theme! Great job! Here is my detailed feedback:
THEME 5\5
I think do not much I need to say about it. Is an ecosystem simulator, as it should be!
GAMEPLAY 5\5
The gameplay is smooth and simple to understand, the encyclopedia is sooooo good. Really a lot of effort here, and I can sped a lot of times to read each species characteristic.
CREATIVITY AND ORIGINALITY 4\5
Even if I've seen many ecosystem simulator, I think is quite original the idea in general, and the encyclopedia is really a boost on this area. Great job!
VISUAL AND AUDIO 3\5
Sadly I've give you only 3 starts, since audio is completely missing. The pokem-style artwork are cute and variagated, you did an amazing work here! I would love to see some implementation on the background and the soil, tough.
OVERALL EXPERIENCE 4/5
The game is what you expect from a well-structured ecosystem simulator, with a simple but at the same time quite complex food-chain system, with producers, herbivorous and carnivores. Keep up the great work!
If you think you want to keep developing this, and you need music\sfx, just write me I will really like to help on that!