One day in 2016 YouTube suggested me a video of Karl Sims' Evolved Virtual Creatures and after watching it and watching a handful more videos of similar simulations that demonstrated machine learning with evolutionary algorithms (links listed below), I felt this concept was one of the coolest things I had seen in a long time and immediately wanted to learn how these simulators work.
(There are plenty more videos of these types of simulations on YouTube. These just happened to be the ones that I originally watched.)
I went ahead and found a couple of articles online that explained the basics of neural networks and evolutionary algorithms, and to my surprise, the theory seemed quite simple and straightforward given the rather impressive results. Of course, it was also possible that I might have just missed some of the more complex details.
I thought: "If I've understood everything correctly, then I should be able to just create a simple simulator like the ones I saw on YouTube. If it doesn't work, I clearly need to go back and study more theory."
So - purely to check my understanding of this topic - I decided to spend a couple of weeks of my semester break to create my own "evolution simulator" and indeed, it pretty much worked on the first try. I also very much enjoyed that I could now create my own creature designs and watch them learn, as opposed to just watching a video on YouTube with a pre-made simulation. (At the time, none of those videos I watched had any download links to any kind of interactive executable. They all seemed like pure demonstrations of the results of research projects on this topic.)
After my next semester at uni was done, I spent a little more time to finish up the project (which I made in Unity), and decided to upload it to itch.io, the App Store and Google Play for free. I assumed there might be a dozen other people out there who would enjoy this kind of demonstration of machine learning as much as I originally did, so why not just make it available for them to download as well.
I was skeptical at first about whether or not I should even bother exporting and releasing mobile versions of this because why would anyone want to run such a simulation for a long time on their phone and drain their battery, without being able to do anything else with their phone in the meantime? But since it wasn't too much effort, I did it anyway.
It turns out that my initial guess for how many people would even find this game and enjoy it was off by a few million, with most downloads being on mobile platforms…
Given the continued high interest in this particular execution of the "evolution simulator" genre, I have since then spent more time working on various updates, including overhauling and improving the creature editor, adding more creature settings, wings and a flying task, save file imports and exports, lots of general usability improvements and much more.
Due to the additional amount of time spent implementing these updates and the continued regular need for maintenance to keep everything working on the latest operating systems (especially iOS and Android), I changed the download price from free to $2 in 2022 on most platforms. Unfortunately, the "pay what you want" approach on itch.io would not have allowed me to continue spending any time on this project.
If you can't affort the small price but would like to use "Evolution" for free on your computer, you can still download the source code and build the application yourself using Unity (which can also be downloaded for free).
A big thank you here again to everyone who has supported this project over the years, whether by voluntarily donating or by purchasing a copy, or just by recommending it to others and sharing GIFs of your creatures.