Everyone was dying to know what Wright would do next. Not one to glory grab, he quickly set to work on two new sims: SimEarth and SimAnt.

SimEarth: With Fred Haslem, Wright co-designed SimEarth - The Living Planet in 1990 based on the Gaia theory of James Lovelock. "Lovelock was working pretty closely with us on SimEarth and so I would send him copies of the game every few weeks"
Probably the most ambitious of the Sim games, SimEarth put the player in control of an entire world. Through careful management of the biosphere, geosphere and atmosphere players could guide a world from its molten beginnings to the advent of terraforming civilization, though the impatient could just drop humming black monoliths on everything.
Although as a software toy, the game does not have any required goals, the big (and difficult) challenge is to evolve intelligent life and an advanced civilisation.
Although the game was much admired when it came out, it was not a big seller compared to its hit predecessor SimCity.

SimAnt: In 1991, Wright and Justin McCormick designed SimAnt - The Electronic Ant Colony, a scientifically-accurate simulation of an ant colony. In this game, it put players in control of a colony of pests as they mated, tunneled, hunted for food and even waged wars. SimAnt was inspired by evolutionary biologist Edward O. Wilson's famous studies of ant colonies. Wright became fascinated by Wilson's explorations of "emergent complexity" the idea that individual creatures operating with very simple goals can collectively produce incredibly complex behaviors. In the game, SimAnt players assemble an anthill and then marvel as it seems to grow a mind of its own. "Each ant is only doing a few simple things, but when you put tons of them together you suddenly have these really surprising results," he notes, including unusually complex ways of gathering and moving resources around.
"It surprised me that no one had ever done a game about ants, and I kept waiting and waiting, and they never did. So it felt like something that I had to do, because I wanted to play it."

SimCity on SNES: When Maxis came out with SimCity, Miyamoto saw it, and was quite taken with it, and he wanted to have it on the Nintendo. "They called us up and said that we want to do it, and they flew me out to Kyoto for a week, which I spent with him working on the redesign for that".
In this Nintendo version, you could gain rewards when you accomplished something big (like getting 50.000 inhabitants), like the mayor's mansion, casino, parks, etc. There was also a season change and an assistant, "Dr. Wright", who gave helpful advice when the city was having problems like a meltdown, monster attack or just a lack of funds.
Shigeru Miyamoto

SimCity was originally going to be released simultaneously on the NES and the SNES, as Nintendo had acquired the licensing rights to develop console SimCity games.The two versions would be almost identical aside for some slight graphical and musical alterations to compensate for the NES's age. However, the NES version was dropped at the last minute, perhaps to promote the new console with its exclusive software.

Skychase: SkyChase, released in 1990, is a fast-paced jet combat game and flight simulator that promised accurate jet-flight physics and fast, smooth action, with seven different jets to choose from. All planes have different characteristics that require different handling methods. In the two-player option you can engage in head-to-head combat with a friend or solo against the computer.

Robosport: Robosport, released in 1991, is a strategy title where teams compete against each other in organised wargames. Each team starts with four units, and on each turn you plan the actions of separate units for the next 15 seconds by programming a series of moves. Up to four can play at once, either take turns on the same machine, or through a network.
For a strategy title, it is simple to the point of perfection. And though the graphics and sound might not be the hottest ever, the game could get quite addicting.

SimLife: SimLife, which came out in 1992, was designed to be an artificial intelligence type replication of evolution and ecology. The concept of the game is to simulate an ecosystem; players may modify the genetics of the plants and animals that inhabit the virtual world. The point of this game is to experiment and create a self sustaining ecosystem. It was slow and buggy, and wasn't a very realistic simulation of ecology because it was so simple. Nevertheless, it was a fun game to play with, mostly to watch the animals you make eat each other, mate, etc...

SimCity Enhanced: In 1993, CD-rom became more popular and Maxis created an enhanced version of SimCity for it. In this version, the graphics were improved a bit, but the most important feature was the full-motion video. Hollywood actors played the roles of SimCity officials like the Newscaster, Police Chief, Fire Chief etc. With every event, like a disaster, money shortage, high crime etc. a video popped up with an actor explaining what was going on.

A-Train: In 1993, Maxis released a train management simulation. Besides being a trainsim, there's the 'triple challenge' of developing a railroad network, building a thriving metropolis and investing all your surplus cash to create a burgeoning financial empire. Running a successful railway stimulates growth in the neighbouring hinterland, with residential blocks, factories and offices being built around the stations. Once you've started to develop the land, the computer takes over adding its own residential and commercial districts.
A construction set for A-train was released about 6 months later.

Unnatural selection: Late 1993, Maxis released Unnatural Selection. In this game, which focuses on genetic engineering, you need to breed creatures that would fight to regain control of an island. It's letting you design and breed creatures (called Theroids) in the experimental breeding lab, controlling their physical attributes, fighting behavior, and mating urges.

SimFarm: SimFarm is one of the lesser-known of the many Sim games It basically consisted of owning a farm in a simcity-type atmosphere, managing crops and livestock and dealing with a town nearby which you didnt have much control over (you got to vote on what they would build). The interface wasnt all that great (for instance, if you sold a cow, you couldnt choose which one, one of your cows would just randomly disappear) and the real key to the game was importing high-priced crops like oranges or strawberries from the crop database. Livestock were a pain in the butt because they would eat the food in like 2 seconds then break out of their pens and eat your crops. And of course, there was the simcitylike disasters like tornados and floods that would come ripping through your farm.

After these games, a sequel to SimCity was expected. However Will Wright had something else in mind; A game called "Dollhouse".

1993: Dollhouse