you can select (and deselect) cards by left-clicking on them, and you can view the contents of a deck by right-clicking it. by selecting certain combinations of cards, you can perform an action by clicking the button in the bottom-right corner. the button will show the available action,
by selecting a pair of cards with a matching symbol, you can perform an action that corresponds to that symbol:
- triangle (ships): click on a deck, and choose a non-discarded card from it (not greyed out). that card is placed on top of the deck.
- diamond (nebulae): click on a deck, and choose a discarded card from it (greyed out). that card is returned to the deck.
- star (stars): click on a deck, and choose one of the two cards provided from it. the chosen card is placed on top, and the other on the bottom. you may do this twice.
- circle (planets): click on a deck. its top card will be moved to the outpost area if possible.
if the two cards selected for this also share a color, the action can be performed twice (or four times for stars). you can stop an ongoing action if you can't or don't wish to use it further by clicking the button again.
by selecting four cards of the same color and differing symbols, you can 'launch', filling in a corresponding voyage circle in the top row. when you fill in all eight voyage circles, you win!
if at any point you cannot take an action, you lose.
stellarion is published by inPatience games and was designed by Shadi Torbey, who also designed a number of other solitaire games that i'd recommend.