Who Wants to Live a Million Years: Analysis of a Natural Selection Simulation

On my fourth generation, and fourth try, I finally survived for 1,000,000 years. It took this long for me to figure out that I need a lot of genetic diversity to have a better chance at surviving. This indicates that today's species need to have diversity to survive. Humans do not have very much genetic diversity, but we have a very large population and a high growth rate, which allows us to thrive. There are many events that can come suddenly (tornadoes, hurricanes, earthquakes, volcanoes) that can put a major dent in a population if they don't have the right traits.
Initially, I started out with little diversity. The majority of my choices were short, with plain fur. However, I also had at least one tall creature in each round, and this is the one I found to survive the longest. This phenotype was able to survive all events except the cold. The long legs made the animal fast, while the height helped it stay cool in the heat and reach tall plants.
Genetic Drift played a major role in this game of chance. The more events that occurred, the more likely the chances of genetic drift were. When catastrophic events, such as volcanic eruptions, happened, some of the population died off unexpectedly. The few organisms that die, die with their genes, and all of their diversity.
The dominant traits in this game included long legs and fur. These were most frequently seen over the generations, and they were the most beneficial. Long legs can be used to run away from things and to stay warm, and fur can be used to stay warm. Because of this, when the years passed, these creatures evolved to have fur and longer legs. The most recessive trait in this game was stripes. Even if you started out with a striped creature, they disappeared quickly.
The traits needed for cold conditions were short legs, fur, and extra fat. These helped keep the creature warm in this harsh environment. The fat would act as the extra food storage for the animal, if food wasn't available. In the heat, the creatures did not need extra fat or fur because they needed to stay cool. Long legs also helped the animal stay cool. Besides helping in the heat, long legs were also needed to run away from new predators. Stripes helped the creature stay hidden in their surroundings when their enemy was on the hunt. When a new tall food source evolved, long necks or long legs were necessary to reach the food.
After attempting this game over 20 times, I have a few suggestions that could make this game more realistic. My first suggestion is to have more little events, such as common natural disasters. To make this possible there would need to be multiple habitats that the creatures would have to adapt to. Over the course of the game the creatures would be forced to migrate to a new region due to an outside force coming in. A force that could be part of the game to make it have real-life conditions would be humans. They ruin many animals' habitats each day, so it only seems fit to have them be part of the game.