Starburst Slot by NetEnt

Purple void, distant stars, a glowing planetary ridge along the bottom of the screen. The gem symbols - yellow octahedrons, green hexagons, orange pentagons, blue and purple diamonds - pop hard against that dark canvas. A gold BAR tops the paytable at 2,500 coins for five of a kind, the Lucky 7 pays 1,200, and the yellow gem sits at 800. Ten paylines evaluate in both directions, left-to-right and right-to-left, so three matching symbols landing on reels 3, 4, and 5 still pay. That bidirectional setup pushes hit frequency to roughly one in every four or five spins. Most of those wins fall below the stake, but the balance moves in gentle waves instead of cliffs. Operators figured this out early - Starburst became the default free spins giveaway precisely because the cost per bonus spin is predictable and the variance stays tight.

One feature. The rainbow-coloured Starburst Wild lands on reels 2, 3, or 4, expands to fill the entire reel, locks in place, and all other reels respin once. If a second Wild shows up during that respin, it expands and locks too, triggering another respin. Third Wild, same thing. Three locked centre reels leaves only reels 1 and 5 spinning freely, and matching high-value symbols on both outer reels pays across all ten lines in both directions - that is the 800x ceiling. No free spins round exists. No bonus screen. The synth soundtrack builds during the expanding animation and the locked-reel respins create a feedback loop that works even when the actual numbers are small, which is probably why this game from January 2012 still sits near the top of most-played lists across every major regulated market fourteen years later.