My help on level 15 is: have you tried to "translate" the lights? What language could that be? Thats the clue that I got from the developer. Awesome game still. I'm loving it.
The developer asked me to vote for their app for best trivia game and to spread the word. So not sure if you've done that yet but the link is on the web search button. I'm on level 21 and still going strong.