Here's the twist: After you beat the game, you're stuck with the ending you get on your first playthrough (so long as you play along with the limitations of the platform and don't go deleting your browser cache). You don't get a second chance. Hence the name.
There's only a handful of decisions you can make during the last six days on Earth, but each one has an impact on your final, final destination. Choose wisely! Wait, what are you doing? No, don't do that! You'll regret it forever!