The game seems to assume you have a QWERTY keyboard even when you do not, which caused a couple misses in the beginnign before I figured it out.
Granted, I decided not long after that actually, a far better way to play would be to just smash keys at random, so humanity would not be safe in my hands regardless.
I agree with the others that the letters aren’t always clear enough. A better solution might be to ask players to spell out increasingly complex words instead, though homophones would still need to be avoided.