Really nice and focused game and very polished

I like the idea and the sound is great. Some challenge would really make it a lot more engaging, though. Like adding a timer or playing against an AI. Maybe also give the player the option to complete the word without flipping any more cards if they know it. It became a little tedious for me to search for the correct letters when I already guessed the correct word.

Nice game, I enjoyed the sound effects a lot, added a lot to the making it feel as if I'm actually flipping cards. One thing I would change is there is a lot of UI elements without labels, for example, there is a slider in the options menu that I just had no idea what it did. That also somewhat goes for the top right counter, so if I were to make one change I would just label those to the player so it is a bit easier to understand.

Besides that, Nice Job :)