Looks like a nice straightforward game! Torpedo in German is... Torpedo. It's actually the Latin name for electric ray fish. They paralyze people, I'm assuming like torpedoes paralyze and sink ships? As usual the important part is that it sounds cool. Anyway... IPA is necessary, I agree. Otherwise if I get a word that clearly looks Russian I don't have to worry about the meaning. It's too easy to recognize the language based on font or special characters. That increases the initial difficulty though. Embrace that and make the game about learning IPA as well! First you get easy words with IPA alongside them, later on you only see the spelling after you've guessed based on its pronunciation. You might want to also consider text-to-speech for lower difficulties (because TTS can still only handle simple words...)? What happens when you get one wrong? Do you only get 1 guess, or multiple? Is there a time limit for answers? Do I get a "results" screen at the end with a list of all the words I saw? In fact, how long is a play session? I like the idea a lot, and the art style of the mock-ups is great, that's why I want to make sure you don't end up skimping on gameplay design, sorry~