Surfing the net on a boring Sunday afternoon and suddenly I stumbled across a miracle... for a lot of time I had been searching for a 'planet manager/play God' type game and SimEarth met all of the requirements.
Upon entering the game and selecting a random game to begin to learn to play from scratch everything seemed a bit overwhelming; there were many 'on-the-side-menus' that weren't visible from the go but I didn't let it fool me - I could see there was fun in this game right from the go after a quick cruise through the navigation of the game.
You can alter nearly every aspect you can think of relating to life management and planet management; a life form's susceptibility to mutation, continent drift, amount of volcanoes, rainfall, sunlight strength... anything and everything. And just a small adjustment in any of the settings can affect the entire outcome of the particular scenario you are playing. But if things aren't going well you can go back and change them again - nothing is set in stone; that is one of the many marvels of the game, the flexibility and the replayability.
Starting from the Geological Era you shape the planet from a molten blob; ice meteors can speed up the process of producing oceans which will harbor the first signs of life - bacteria. Watch in
awe as the seas begin to fill with life which slowly evolves onto land. Eventually civilization develops which you patiently watch or you can mould it to your wants. The marvel of civilization on SimEarth is that any life form has the potential to turn sentient - fish, crustaceans and even mammals (but that would be a bit stereotypical wouldn't it).
A series of scenarios to play (call it the campaign if you will) will keep you busy for hours; face the challenge of terra forming familiar planets such as Mars and try and start biological life over again after a cataclysmic event effects the history of Earth forever (I'll let you find out about that!).
But you don't have to leave all of life's developments to chance; you can place many different objects to speed the process such as oxygen, carbon dioxide and nitrogen emitters to affect the atmosphere - but be warned, everything has a consequence and you will need to think hard about what you are doing! You can also place life forms directly to the planet (provided you are in the correct era) to speed up evolution and then you can try and develop sentient life with a monolith as found in 2001: A Space Odyssey.
I'll leave you to enjoy this fantastic game which will keep you occupied for hours and discover the miracle of life!