I'd like to introduce to you a riddle game that is of my creation. It is called The Fortress and it is a thriller combined with extremely hard riddles.
The idea is simple, you see a picture and you need to find a keyword (or keyphrase) that is an answer to the riddle. This answer is usually hidden, sometimes encrypted, sometimes clearly visible... But sometimes you need to investigate a little to get it or just to get another hint that will bring you closer to the end.
The game is available on iOS, Android and Windows Phone.