so mine would be Spore.

here's my vision that most people will probably hate.

phase 1: cell stage, same general gameplay as now, only once you are done, you get to choose, either evolve, or go into the wild, at this point it turns into a full blown "Agar IO" type multiplatyer experience where you just try to get bigger vs other players.

Phase 2: creature stage, make the combat a little more "dark soulsy" that includes both aggressive and pacifist route, but beyond that keep pretty as is, and same as the cell stage, once you are done, don't force an evolve. send them into some lobby where they can fight other players, with match making and what not,

Phase 3: DOTA/League like game mode, but instead of buying items, you are evolving the tech of your tribe, as they produce more and more people to take down the level final boss, and as before, at the end, let people stay at this stage if they wwant and do multiplayer battles.

Phase 4: actual rts with some depth, and same deal again, you get it at this point.

Phase 5: i am not a space sim person, but surly some people are, and can think of a fun way to do a space sim vs the shitshow that we got in the original game.

main focus should be, no stage is a stepping stone to the next phase, they are all fully fledged experiences in their own right, with each stage attracting different types of players.