Here's a representation of the 300 brightest stars in the sky. Although the transposition of celestial position to 2D (using the equatorial coordinate system) isn't perfect, especially at both poles, the star's size and color accurately represent its apparent magnitude and spectral type color. There are two game modes, SPRINT and MARATHON. On SPRINT mode, you try to get the most points during 5 minutes. Points are given each time you click (kill) a star, you get more points for a brighter star. On MARATHON mode, you try to click (kill) all 300 stars the quickest possible. The final score is the time you took to do this task, lower is better obviously. On the panel at the bottom, there's a bar for each type, when the bar reach the magnitude of a star of the same type it starts twinkling, it passes from 'off' to 'on' state. When you click on a 'on' star, the bar falls to a magnitude of 4, but the rate of the bar improves accordingly with the magnitude of the star clicked. Finally here are a few things to help you play the game. You can use the keyboard to move in the game instead of the mouse, just press K to go in that mode, press M to use the mouse again. In keyboard mode use WASD or the arrow keys to move. You can switch anytime in the game. Another helpful tool is the zoom, press Z to go at 1x and see the whole map. You cannot click the stars at 1x but you can use a view window and drag it to where you want to go, then press Z again to go back to 5x and continue playing.