Presumably it's a random batch of words since you can run the test again. I wonder how much the word selection affects the outcome. I got 66,750 with 20/20/15/17/14.

I'm curious how the difficult is chosen because "obfuscate" was included in the hardest difficulty but I would not consider that to me a difficult word.

Also I found that some of the definitions were not completely correct.

It could be based on things like word frequency. I'd expect obfuscate/obfuscation to be less common outside of programming and RPGs (Vampire the Masquerade).