Gem Swap

Gem Swap is an eight-by-eight match-three board in six colours. Click a gem and then a neighbour; the swap only holds if it forms a row of three or more, otherwise the gems slide back. Cleared gems drop away, the ones above fall down and fresh gems come in from the top, so a single move can start a cascade. The board is dealt without any ready-made rows. Free, no sign-up, plays right in the browser.