I’d like to bring up as a biologist some ideas that could enrich multicellular stage gameplay and concepts.
Also, opening a big parethesis. Pardon if there is/was a topic about this before or this was set already, I didn’t see it; but I feel we should set a biological species as a goal so we can focus a bit better on what tools we need to give to the player. Like, Thrive will be “ready” when a player can start as a microbe and completely mimic X, Y and Z IRL organism (an Human, a Lion, a Sargassum, Prophyra, and a Bee for example).
In this case I elicited above, if a player can mimic all of these three organisms above, starting for microbe, then to multicellular and finishing in macroscopic, it probably can do anything they have in their minds which I think is the goal of the game, as a sandbox evolution game. (I’m treating post-macroscopic stages as a it’s own separate soft-science-fiction thing).
Personally I think algae are good candidates due to their immense diversity in niches, I will use them as example.
I aggree with what was said before in this thread about what multicellular should be about: trial and error, specialization and optimization. If we look at the basal eukaryotes and algae, there are multiple “simple” multicellular organizations. I will bring this image of the Ulvophyceae family, which brings some macroscopic organisms with different cell organization strategies (Ignoring the phylogeny). I also didn’t see Dictyostelids being mentioned here. They are great models for evolutions of multicellularity, reproduction and signaling.
Each organization could give different buffs regarding energy required to increase the colony, also these are present in plants, fungi, animals and others.
Now for reproduction:
I think something we could do is give small variations within the same species and when you sexually reproduce you get the chance of getting that part for free + a bonus in base MP (complexity in life is probably due to whole genome duplication events). We could display that chance in the editor too.
Maybe we could actually change the aim of multicellular to that: increase the MP cost of each part linearly with size but increase base MP geometrically with sexual reproduction. Maybe having a chance of horizontal gene transfer when engulfing. Make the player chase the chance of polyploidy for that increased base MP, as that grows geometrically, it creates a smooth transition to macroscopic.
As for specialization, we could initially make it be an active option every time a cell duplicates, after the player has two or three cells, it will get a bit annoying, so we could give in an option that locks that cell into a type and goes automatically. In cyanobacteria the organism can differentiate a cell either into an heterocyst (metabolism) or an akinete (survival), however, in a scenobial algae (colonial), cells are determined to differentiate as in scenedesmus.
Some interesting papers:
https://www.nature.com/articles/s41576-023-00688-5
https://www.nature.com/articles/s41586-025-09808-z