I've played this for a few hours now. It's an interesting concept with a chance of providing a kind of gameplay I haven't seen before. Guiding an evolving population towards greatness by trying to cleverly select, breed and kill individuals is something I haven't seen before.
The game provides you with various tools to filter out and find individuals that have the properties you like. At first you just look around and select individuals that do stuff you prefer, but soon you realize how slow that procedure is and you quickly start to crave more powerful tools like "hmmm is there any way I can select all individuals that have at least 1 kill, but who are also not exhausted, and then breed all of them at once?". And the game provides those tools for you, so it's just about trying to make a clever guess about what would work, and trying that out.
The game is obviously not done yet, and it's a little confusing at times. For example, it took me a while before I understood that I could only select and breed BLUE pixlings, because I hadn't understood that the RED pixlings were from another team.
But it's still kinda captivating. I think feedback from beta-testers on a site such as this is exactly what it needs at this stage, to figure out how to refine it. I messaged the developer with a few suggestions and one of them was even implemented the same day!
I noticed it runs like 8x faster on Chrome than in Firefox (at least on Linux). I like how it easily deals with scale, having thousands of little critters at the same time, and with good framerate (in Chrome).