That's a great site! But the words certainly are not easy ones. I got lucky on a few of the ones I'd never, ever heard before. Quite a few of the words that I hadseen before are not part of my active vocabulary. When I stopped, I had managed to hit 48 -- but not without a little help from Lady Luck.
It gets a bit boring after a while. I was surprised at the number I guessed right. I've never seen some of these words before! Others, by coincidence, I just read within the last few weeks.
They are difficult. Sometimes, I must use deduction logic to eliminate known words to guess right. Anyway, I got to level 36 then it kept dancing around that mark for the next 440 grains before I quit.