Reviving the topic somewhat to chronicle some thoughts I had while balancing timed-reproduction earlier. Implementing a new ammonia/phosphate system slightly exasperated the early-game problem, where, as a single piece of cytoplasm, you don’t really have many options in regards of interacting with your environment. This can make the early game a bit of a drag, as you don’t really have to make many decisions besides, as Thim says, keeping half an eye open for colored clouds. This wouldn’t be a problem if this peaceful state happened for one or two generations, but as mentioned, it usually takes a while for other cells to emerge, and then after that, transform into actually competition.
Looking at Earth’s history and the cellular kingdoms, I actually think that cell-to-cell interactions will remain somewhat tame until the arrival of eukaryotes. Bacteria as a whole don’t exhibit many of the complex interactions that we usually see with more familiar lifeforms; for example, the concept of predation was largely an invention of eukaryotes, with their advanced morphological capabilities unlocking many cool adaptations. Bacteria are entrepreneurs of toxicity, so it’s not like they won’t present any threat at all to the player. But we should be aware of their limits.
As such, we should look to introduce other challenges and threats for the player to confront, and I think the player’s environment should fill that role. Life on a young planet is incredibly dramatic. Volcanic activity is rampant, the oceans are very warm, and meteor bombardments occur very frequently. This means good things for game design; we can implement a heightened state of chaos in the beginning of the game, and then reduce the frequency of these events as the player’s cellular competition begins to mature and take hold. The early game hydrothermal vents could feature a lot of lava to represent the beginning of intense geological processes for example, and we could implement exploding rocks (an actual thing which occurs when wet rocks are rapidly heated) as an environmental threat in certain regions.
I won’t elaborate much more than this since world-shaping will be the focus of 0.8, but early environmental hazards can be an answer for some of the early game problems we have.