I love any kind of adventure game but I prefer RPG style though I didn’t play any real video games recently apart quick games such as cards games…
One kind of game I would like to work on is a RPG style where the players would progress by learning a new language. I don’t mean programming language but dialect. I hope that’s the right word and you got the idea. The player will learn the language but also how to read it. For example, he will have to decipher symbols to escape from a crypt … All that with great 3D animations… 
To learn the language he will go to a school and progress through lessons…
I’m thinking about Japanese since this is one of my favourite languages.