Pretty cool game :) simple and fun. 4.9/5, still has room for improvements
A few comments:
1) I only got green ball once maybe it's just random, but I always changed to red, blue or yellow, never green
2) Maybe as an idea to make it harder you could change the speed of certain balls, and not make all of them go at a same speed.
Good game, but it DOES get easier, instead of harder.
All you really need to do is focus on reproduction + attack or reproduction + defence and you will win easy.
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