Press space to select "Play", then click on one of the three lots to draw it and see your fate! Whoever draws the marked lot is thrown overboard.
Once you've drawn a lot, you'll have to press escape and launch the game again if you want to give it another go. Maybe I was too lazy to implement a reset feature. Maybe it's an innovative rouge-like mechanic. Maybe it's a commentary on the finality of fate and death. You decide.