I had mixed reactions about Spore. The ambition/breadth of gameplay was impressive. The creature creator was impressive, and it was fun to see other people’s creatures show up in-game. I was disappointed at the shallowness of individual stages, how little earlier stages affected later stages, and the tediousness of space. I think without the pre-game hype, the balance would have been more positive feeling than negative for me, but I mostly remember it as few gems wrapped in disappointment.

Put a lot of hours into Paradox Interactive games

Endless Sky looks cool. Definitely going to give it a try.

My two favorite open source games are Thrive and Cataclysm DDA

Thrive is an evolutionary survival game. Similar to Spore, you start as a single-cell microbe. You gather nutrients, evade dangers, and evolve adaptations. Eventually, you can progress to the multicellular stage, then macroscopic, etc. up to spacefaring. Currently everything after multicellular is placeholder, but the cellular gameplay is fun and has enough viable strategies to make replaying interesting. https://github.com/Revolutionary-Games/Thrive

Cataclysm DDA is a zombie-survival rogue-like simulation game. You start as a single survivor and need to scavenge for food, shelter, and protection. If you like games that focus on system/simulation complexity over visuals (e.g. dwarf fortress) I’d recommend this one. For example, the vehicle system allows you to build custom vehicles, which can be anything from a dinky wooden bicycle to a monstrous RV-turned deathdozer+mobile base-on-wheels. https://github.com/CleverRaven/Cataclysm-DDA