Please help me figure out the meaning of the phrase "run roughshod over gems" in the following sentence from the description of the game Harry Potter: Puzzles & Spells:
Bathroom trolls run roughshod over gems.
Please see the photo of gems below:
For more context, this is a match-3 game. Please see the following description from a different source:
Prove your Match-3 skill by beating levels to upgrade and unlock new spells and magic abilities which will aid your quest to conquer more difficult Match-3 puzzles. Get a chance to upgrade your spells as you prepare for the magically mischievous challenges ahead. (Google Play Store)
Here is a photo of a bathroom troll: