If you’re still taking indie demo suggestions, I’m sharing Primal Strain on behalf of Portal Rabbit. You draw your own creature, choose its stats and abilities, then gather food, build nests and raise a brood while competing with rival species. The creature you draw is the one you play.
It’s a free, single-player browser demo, still in development and made with generative AI assistance. Desktop is recommended and there’s no game account or download: https://portalrabbit.com/games/primal-strain/
There are also dwarf-mining management and fortress-building swarm-survival demos if those sound closer to your interests: https://portalrabbit.com/game-demos