I'm glad you liked the concept! I was definitely pretty happy I came up with it so quickly lol, I got lucky in that regard. I should have tested the Web build on my laptop/anchored the UI, that was a definite oversight.
I also strongly agree with the idea that the revealed letters don't "feel earned" - if I was to work on this further, the biggest change I'd want to make to the gameplay is somehow tying your responses to what gets unlocked. Maybe right letter in right spot = letter gets revealed, or what I really want to do in my head is have "similarity scores" like in Contexto, where if you guess a word that's very similar you are told that. Or if I was doing more like 3- or 4- word phrases, have it so any time you get a word right, it gets revealed, but you still have to get the whole phrase.
I really appreciate you giving it a try, and its good to hear that you had a very similar thought regarding how to make the gameplay better - thank you again for the kind words!!