King of Olympus Slot by Playtech

Wins here work on count, not lines. Land eight or more matching symbols anywhere across the six reels and they pay, then burst and let new symbols tumble down into the holes, which can set off another win on the same spin. Running alongside that is a multiplier bar that opens at zero and climbs by one for every separate win a spin produces. Once the tumbling stops, the bar's final figure hits the whole spin's winnings in one go, so a board that chains four or five drops pays far harder than any single match would.

The glowing orange Fireballs are what turn that slow tick into a jump. Each carries a value, and when one lands on a spin that pays, its number gets added straight to the bar. A Mystery Fireball keeps its figure hidden until it flips, and it can come up anything up to x500. The two golden braziers burning either side of the reels help here too, since either can spit a Fireball onto the grid on any spin. In the base game, though, the bar wipes back to zero the moment you spin again, so most rounds it never gets far.

That reset is exactly what the free games remove. Four, five or six-plus of the grey-bearded Zeus award 10, 12 or 14 games, and for the whole run the bar stops resetting between spins, it just keeps stacking, which is where the round earns its keep. Fireballs stamped with a + drop extra games on top whenever they land with a win. If you don't fancy waiting, an Extra Bet toggle raises the trigger odds for an extra euro on a five-euro stake, or you can pay 75x to drop straight into the round. All of it sits under a bright blue sky split by forked lightning, gold marble columns down each side, with a ring, a chalice and a blue lyre among the treasures and a scatter of cut gems below.