YMMV / SimEarth

• Annoying Video Game Helper: Will Wright himself in the Turbografx version. The main reason he's annoying is because the advice he offers on each scenario isn't very helpful (over the years general strategies for each scenario have emerged, and none of them match what Will Wright suggests. Ironically even though Will Wright wrote the game, he apparently isn't very good at playing it.)
• Character Tiers: Enforced due to different species having different likelihoods of attaining sentience. Robots are the most likely if introduced. Below them are mammals and dinosaurs, the most likely sentient species to occur by laissez-faire play. At the bottom are Trichordates, which even The Monolith will frequently fail when used on, and below even that are Carniferns, which not only need specific conditions to appear in the first place, they are very difficult to control enough to develop intelligence before another species beats them to it. Still, though, sentient carniferns.
• Fridge Logic:
  • Traveling sentients can be seen riding horses or horse drawn carts, even if mammals do not exist on the planet.
  • It's possible for civilizations to settle in polar regions, which on the surface doesn't seem too odd. But the world map uses an Equirectangular / Plate Carrée projection, which is fine for most purposes but notorious for inflating polar regions. So even if there are many towns on what seems to be a gigantic landmass, they could in reality be very cramped together.
• Funny Moments: What's the one thing that can halt a robot infestation singlehandedly? Daisies.^note The game will try to prevent structures for other species from being built on Daisyworld, but it's not impossible.
• Game-Breaker: The Monolith, which allows you to choose a sentient species rather than wait for evolution. Risky in scenario levels due to the high energy cost — and soft-disabled in Hard planets by costing more energy than the Cap can hold — but not in modes where energy isn't a factor.
• Nightmare Fuel:
  • It's possible (and common, if the monolith is used too early) for intelligent life to completely die out. If this happens, you will be notified that civilization has collapsed and, to rub salt in the wound, the planet reverts to the evolutionary timescale speed.
  • Just how easy it is for the Nigh-Invulnerable robots to take over when even one is introduced. Unless you're intentionally trying to unleash them, seeing your carefully built up biosphere being wiped and cornered, robotic tiles becoming more and more common, can be fairly distressing.
  • The Plague, particularly in the SNES version. Basically, it's represented by an animated skull-and-crossbones symbol with its jaw moving up and down. While creepy in and of itself, it's accompanied by a disturbing sound effect of distorted voices saying "No! No, no, no, no!" (presumably to represent the dying victims).
    • According to the SimEarth SNES instruction manual, Plagues are "not useful for anything but destruction".
• Periphery Demographic: A significant portion of the game's main player base after the mid 2010s is aspiring writers using it as a worldbuilding tool.
• Porting Disaster: The Super NES version not only dumbed down the terminology (e.g. "whales" instead of "cetaceans", "starfish" instead of "radiates"), but it had trouble handling particularly complex maps. Trying to save on one of these results in most of the world's landmass being erased in an attempt to force-fit it into the cartridge's memory. It's little wonder why even Nintendo's Virtual Console skipped over it and opted to sell the Turbografx version instead of the port on their own system.
• Spiritual Successor: Maxis' "SimEverything" game, Spore (released 18 years later).
• Unintentional Uncanny Valley: Ironically, despite the MS-DOS version having the simplest graphics, it puts a realistic human face on Gaia rather than the cartoony eyes and mouth that the other versions opt for. Combined with its jerky facial movement, this Gaia looks incredibly creepy and scared a lot of younger players.

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