For a slightly more (but still pretty easy) hardcore simulator, try Air Traffic Chaos. It lets you act as an air traffic controller, minus the stress-related nightmares and high-rate of suicide innate to the profession.
Then, of course, there's all those "Catz", "Dogz", "Horsez" and "Hamsterz". They might be alright, but I've only ever played the original "Catz" for PC (which was excellent).
Also, there's "Aquarium by DS" (and it's sequels- "Fantasy Aquarium by DS" and "Deep Sea Aquarium by DS") which is an excellent aquarium simulator. It is nicely detailed too, and even allows you to change the temperature of the tanks.
And who could forget the near-simulation of farm life: "Harvest Moon DS" and it's sequels.
Then, of course, there's all those "Catz", "Dogz", "Horsez" and "Hamsterz". They might be alright, but I've only ever played the original "Catz" for PC (which was excellent).
Also, there's "Aquarium by DS" (and it's sequels- "Fantasy Aquarium by DS" and "Deep Sea Aquarium by DS") which is an excellent aquarium simulator. It is nicely detailed too, and even allows you to change the temperature of the tanks.
And who could forget the near-simulation of farm life: "Harvest Moon DS" and it's sequels.