There were a few based on water. Just to keep the answers off of this page in case people don't want to see them, here's a link to all the riddles on GitHub:
https://github.com/SlugGames/LifeIsFullOfInspiration/tree/master/Life%20is%20Ful...
You can view all the java files in those directories to see all the acceptable answers. Also, they were not case sensitive, as the solution text field automatically converts to lower case.