Okay

Needs more trade-offs. Reproduction is free, and eating (or attacking the weak) leads to immortality. This causes degenerate strategies. Also, there is no way to gain energy from the sun, so populations quikly leave it.

Overall, this is a good start, but it needs more balance to stay interesting.

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Update: survival mode adds a lot of fun. The fact that youre playing just one critter and scored only on lifetime makes reproduction a waste of time. Id love to see a mode where youre scored on how many descendants you have when you die.

Tobikuma about Artificial Life