I need to move closer to something important. I want to be vaporized quickly.

If you try the simulator, you’re going to be really disappointed. You really need to be at ground zero to get that effect. Tv over dramatizes the effect.

Additionally, this simulator likely assumes that the warheads will explode with the designed yield. There is a surprising amount of work to rebuild and maintain a nuclear warhead on a regular basis for it to work as designed. If Russia hasn't maintained their warheads, then they might only give fission yields (like Hiroshima), not H bomb yields. At worst, it may not even be fissile and just end up being a dirty bomb.

I'm betting China is doing a better job of maintaining their warheads.