In the game there are a grid of gems, you have to destroy the gems by swapping them. The gems will be destroyed if a line of 3 or more gems of the same kind are there. When some gems are destroyed, new gems will be created. You need to destroy gems as quickly as possible in order to advance to the next level.
You don't need Adobe Flash player which must be desinstalled of your computer because the support of Adobe has stopped on December 31, 2020. For more information, you can read the page on the end of Flash and the start of Ruffle the Flash emulator in Javascript for modern updated navigators.
Many games are not playable with Ruffle and generate a warning message:
"This content is not yet supported by the Ruffle emulator and will likely not run as intended."
Useless to clic on the "Run anyway" button, the game will be not functional. These games will be progressively deactivate awaiting a future evolution of emulator.
Other games start but don't work well. But fortunately, it remains games correctly playables for our great pleasure!