Pretty fun. It would be nice if it colored the pixels on the keyboard letters to match your known hints (e.g. when my guess was F but the letter is P, then when I am on the appropriate column, the T in the keyboard should have 4 green and 1 red pixels on its top row).

In the instructions I think there is an error. It highlights ‘F’ halfway green and in next step it turns out that letter should be ‘E’. Isn’t F subset of E except for missing bottom horizontal piece? Why isn’t the whole F highlighted as green.

interesting concept… I skipped the wordy instructions and found it intuitive. really nicely done, lovely UI (apart from the enter key on the left).

The "Enter" may not work everywhere...