This was a cute and fun little game.
When I first started and hadn't placed anything, the initial chicken started wandering off the grass area. As I'm typing this my critters have eaten everything and are wandering all over the empty space, though do seem to be returning to the grass area from time to time. It doesn't really matter much as long as they are close enough to come back when there is food. It just felt like they had gone off the edge and were floating in empty space.
When I started placing grass, I was really wanting to be able to click and drag to place it. I thought I had it doing that at one point, but then it wasn't working anymore. Later I realized that if you selected the grass you could only place one per click, but if you right click to clear the selection you can left click and drag around to mass place grass. I figured this out when placing workers and it would only place one then deselected. I had been trying to see if dragging would place multiple of them and instead it placed grass. For this style of game it makes sense why you might want to limit the placement to one per click, and I'm wondering if the nothing selected drag to place might be a bug/leftover testing trick.
Once I saw the workers it was also less of an issue, and I placed one. They weren't really able to keep up and I still did a fair amount of planting for a while, but then things just took off. I think the growth rate ramped up a bit too fast from doing a lot of manual placing to not being able to keep up with the unlocks. I skipped over many animals, just unlocking a bunch and placing the latest I could afford. Then doing a round of upgrades, maybe a worker unlock, and then next round of animals. After I unlocked everything I went back and placed one of each.
I left it running while typing this, occasionally adding more stuff, or getting upgrades. It started to lag after a while, though I was still able to interact. Placing animals had the animal preview bouncing all over, but the highlighted square still showed, and it placed fine.
I wanted to see how it would handle if I let it keep going. I placed out 10 elephants and they overwhelmed the ability of the workers to keep up. It looks like they all got caught in a cluster of workers and elephants placing and eating right away, in an endless cycle. I kept increasing the Better Feed and placing more Overseers every so often, to see if they could ever keep up, but the animals continued to dominate. Every upgrade was at least level 25. Eventually I acknowledged that the Overseers were too expensive (~$200 billion), and with all the bonuses the other workers could probably do almost as well, and I could afford a lot of them. When I mass placed a group of them out the game really started to lag as the animals saw the new food and moved towards it. Then all the animals and workers again grouped up. I could then place another group until the lag was too much for clicks to register. I put out enough of each type that the next cost over $1 million. They still ended up clustered after a while, though I now had 2 clusters. I think I've stress tested it enough for now. I know it is a simple incremental game, and I probably went a bit overboard, but it's late and was amusing me to do so. I'll suggest to my partner to give it a play tomorrow.