Hm your project looks a bit like elite, i think the evo concept is not a small niche. Dough it depends on how nice it looks in the end. To give an idea for the apple watch the most popular paid download was a tamagotchi app, civilization was a big name once, several city building games have there been. perhaps a more modern example farmville (bud not a good example, thats more about selling virtual stuff on line, the evo concept is almost gone in it).
I remind a time, where people created eco sims it was not all 3d most often 2d areas filled with water/trees/grass sometimes a height map. and on it simple creates evolved. sometimes using genetic algorythms it was quite popular, more like hoby science. it took quite a while before the concept got into games like i just named.