If the game freezes, just click inside it (games can get unresponsive if you click elsewhere on the page).
Detonate the groups of 3 or more same gems. The bigger the group, the larger the bonus! When you pop them, everything above or around them collapses in on them. Bonuses increase depending on how many gems you detonate. Fit the end of every level the more cleared lines you have the higher the end of level bonuses are.
Use mouse to interact.