I made it to epoch 17 with this one particularly successful sipho and after a while things got a tad stale for me. Every run is only slightly different from the last and eventually you stop finding ways to slightly refine your sipho with the nutrients you have, as you either form a perfect storm ready to wipe out the ecosystem with barely a sweat or die to something that got there first. I feel like there could be ways to make the post-Frakir game richer, and so I'm gonna write some suggestions here. Feel free to use any or none of them, I just wanna write down my thoughts

After beating the breeding grounds a bunch of times I wondered "what if you could have your own?" After all, the hallmark of an organism's success is its ability to pass on genes to the next generation. Perhaps instead of starting every run over again the exact same way (only difference being the order of environments you see) you could establish a nursery within the open waters. After evolving a reproductive zooid of some kind, you can settle down and tend to a clutch of eggs, hunting down prey to feed them and protect them from opportunists. Once they hatch, you can start a new run as an offspring, the spawner (your original sipho) staying behind to tend to the eggs, and go around the various levels without the bosses (as you've already killed them) and gain mutations you can feed to your spawner (I figure since you can steal mutations from the alpha creatures you can give them to others of your kind). I figure you can also carry nutrients you gain in the open waters to each new run, that way there's a reason to go around collecting the abundant nutrients in that area. you also can redesign the spawner in a separate growth menu, that way you can eventually turn it from a smaller creature into your very own Frakir. This spawner sipho will produce whatever design you currently use, but occassionally make copying errors and produce new configurations of siphos, which may even have new mutations you can take and give to the spawner. Zooids from the same spawner won't attack each other, the spawner, or you, and will go out and hunt other siphos in the open waters to bring back food as a pack. But you're not the only one capable of reproduction and gregariousness... Other creatures in the open waters will make nurseries and packs of their own. These packs will each have mutations they've gotten independently, making each pack a new kind of threat instead of nature mutations vs. yours. Over time, territories will emerge between you and enemy packs, which you must constantly fight with for resources (maybe there could be some sort of grazing material that would incentivize a continued presence. In a way, its like fighting a new, bigger Frakir every time you take on a pack, and each pack's nursery is a boss waiting to be slain and harvested for its food and unique mutations, incentivizing players to go forth and conquer the seas with their siblings.

I mainly suggest these changes as it adds new depth to the post-Frakir game, as I've come to call it, and kinda ties things together thematically. After all, why should bosses be the only ones that work together? What if there was more to each member of your own breed than just food or danger? I also wanted to give the open waters a chance to shine, as not only is there no reason to stay there atm, its actually bad to stay too long and evolve in that space cause you wanna get the mutations and, if you evolve new zooids in the open waters, you'd never be able to grow fully in a new run, which made me just try to skip it completely and start a new run asap. I figured easiest way to do this would be to tie mutations back to the open waters, and make each run kinda like a raid on the old regions for your pack. Anyway, I hope you like these if you get a chance to read them, I tried keeping it relatively simple so as to not change the game completely, and as said before feel free to use any or none of em :)

Edit: one more thing, maybe there could be different methods of reproduction based on breed that match with the theme of said breed. I figure the buginis would use budding, as they’re pretty plant like (maybe they’re reproductive zooids are cheaper or they use their structure zooids instead or something). The advena use sexual reproduction, emphasizing their adaptability. Cra’Than are parasitoids that use ovipositors to inject larvae into other siphos. Saenus could produce twin egg sacs, but the larvae develop at different rates and the strongest eats the weakest, emphasizing their resilience and strength. And then the Vagorians are brood parasites, laying eggs in other nests to be tended to by other spawners, as they’re far too nomadic to stay still in a nursery of their own