I had an idea where you gained abilities (evolved) when you die. The idea would be to complete the levels in the least amount of deaths

I think it would be nice that when you took a sphere, you could evolve

I really don't have an concrete idea yet, i'm looking at deep sea creatures youtube video's for inspiration.  

I  like the idea of adding body parts to a creature to make it survive in an alien world, but I also think a lot of people are going to play with similar ideas.