Select the notes that you think make the chord and click on "roll" to submit your guess. There are 10 chords and you get 2 guesses per chord. The scoring system resembles ten-pin-bowling, which means you will be awarded bonus points for "strikes" and "spares".
This game is a weekend project and still a WIP. If it interests you in any way, feel free to send any kind of feedback (including suggestion for a better name) to naikvin at gmail dot com.