1. I loved the game monster rancher, not because it was a good game. Great potential, but not much of a game there. Street fighter had both, more, and better mechanics, also the game didn't have options. But, what made the game special was that it would generate a different monster by reading the CD. With a possibility of 200 different monsters. Now days CDs aren't practical. We could use DVDs, blue Ray's, and USB sticks. We would use aliens instead. Unlocking aliens instead of dragons, and monsters. We could add ships, weapons, and hull types to this. Some one told me they used serial numbers.
2. Another thing I liked was unlocking different fighters. We could do this by both achievements, winning with certain aliens, or winning on different game settings. I again am talking about unlocking different aliens not fighters. We could add techs, ships, hull types, and weapons to this. I think the most hidden fighters I've seen was 18 though. We could add different species picks.
A third idea I liked is how spore gave me tools to create alien picts. I think it needed more alien parts added to the list. Clothing was limited in spore. It would have been nice to of had an option to add specific features.