You must spell all three words in one game to get the achievement. It's possible to do this if you already obtained three words separately because you have some experience and now all you need to do is get them together. A couple of tips:
Focus your attention on spelling ZODIAC first, because this is the word that requires the most effort to be at the top and maybe when you finish you may already have half of the other two.
Avoid the lower area of the board. Just look to spell HERMIT if you're already down but don't take risks. As soon as the green portal appears, go back to the middle area.
Learn how to shoot at the targets required to complete a word. Each one has a different style. Take all the time you need to shoot properly and if you start to miss shots pause the game and take a break.
If you lose a ball since the beginning it's better to restart because you will need it when you are close to spell three words. And if you don't know exactly what to shoot at, check this guide. Good luck:https://steamcommunity.com/sharedfiles/filedetails/?id=16294...