Hmm...I'm not sure how to comment on this. As a gimmick, this is top notch, giving pure fun for a short while. As a game, however, it kind of falls short, because after that short while you grow bored of it.

While the animals are fun for a while, their survival (or lack thereof) seems rather random and not directly related to the choices you make (unless you do something specifically to kill them). I strongly get the feeling that the game will always have 6 species max because they just keep killing themselves or dying randomly and there's nothing you can do about it. As such, there's no genuine challenge in the game, and just watching the animals do stuff gets boring after a while.

The wacky music is very fitting and adds a lot to the wacky atmosphere. The sounds also add a lot and makes the animals feel alive. When there a lot of animals, though, the sounds they make can become repetitive and very grating.

Graphics-wise, it's simple yet charming. The simple graphics have a lot of variety which makes the spectacle fun to watch, but the evolutionary traits are very unclear, and in every case I had to see them functioning before I realized what they were supposed to represent.

All in all, a fairly unique "game" that would work out better as a Flash gimmick than as actual game.

It's only fun for awhile. Afterwards, the game seems to play by itself. Even though the idea is nice and kind of funny to play, it's hard to see this as an actual game by itself.

I have to comment that I was quite surprised by the theme, and this was the best idea I came up with. The complexity of the small ecosphere absorbed the time I wanted to use to add gameplay.
To have a bit of game time left, I decided not to label the evolutionary traits. I wanted the player to play multiple times, to learn and to think at which point he destroyed the ecosphere. Also I tried to create something where the player discovers features I did not think about, due to the high number of combinations. I don't know how many species may coexist, but my maximum is six, too.
I see why it doesn't feel like a game. If I had the time, I would have added goals (reach 6 species; get a creature with all traits; get a species that kills off 3 species) and got rid of too much stupidness/bugs. In that case it would be much more enjoyable probably.
Thanks for your comments.

Interface is cumbersome, icons incomprehensible. However, graphics themselves were clean and functional (wish everything was larger, though) and author deserves huge kudos for being ambitious. Please keep working on this game...

I liked the idea. Although maybe it's not a gameplay heavy game, the mood reminds me of the GROW series (that crazy japanese flash games).

Goals should provide some guidance for the player. I would have suggested a tutorial, but probably goals works too and I feel it's more addequate for the experimental type of gameplay you have.

Kibertoad: Indeed I did not put a much of thought in the interface, but I think it works. Thanks for the kudos, but I am not going to work on this, as my main focus is on a remake of the my last LD game (http://www.ludumdare.com/compo/ludum-dare-23/?action=preview&uid=12423).
Fanatiko: I am a fan of the GROW series (my favourite is GROW RPG), so thanks for the compliment.

Interesting experience. I did not seem to be able to influence game progress much though. It was not clear how the evolution improves survivability of the species.

Mac version please?

I can't add a Mac version because I used Game Maker 8. I can't promise I will use Java+LibGDX next LD, but I am learning how to use a proper tool.
Bvanschooten: I hoped the player would see which food they go for once they got new traits. If you give them wings, they will fly up to the cherries for example. Just the antler has no use sometimes, as they only hunt down tusk animals, which only hunt down peaceful animals.
Because I run out of time, exploration of these facts seemed to be a working way to get at least a bit of play time.

Good ide but I would would expand the game, and include a realistic animals, so like for an example: You would have an option of having long hands, and the new species would be a monkey. I liked the graphics!

Loved this. Though once you figure out the different traits it gets pretty easy to keep an ecosystem going. If you wanted to tweak this for later use you might have different species migrating through, traveling carnivores, and your job as a player is to keep the ecosystem stable.

I originally planned to use actual animals, but that would have made spriting very complex, as I would have needed sprites for all those crazy combinations (what has wings, tusks and antlers?).
Same for events. I planned to have the water level rising sometimes, maybe have traveling carnivores like science4cake suggested. But I just did not have the time.
Thanks for playing!

I liked the abstract style of the creatures. They were quirky. I couldn't work out how I could influence the outcome of the game though.

Not sure how much I liked this. There's not much variety possible and the sound effects quite literally gave me a headache. If you expanded this and made it a bit more diverse I'd absolutely love it though!