It’s “Secret of the Stones Max”, which offers the classic game you already know or the option of a more volatile “max” mode. The main difference is the bonus in Max is enhanced, with picks potentially offering increased multipliers (up to x4 off one stone), extra wild reels alongside the classic 2 and 4 and more free spins. Harder to land, obviously, but the potential is utterly bonkers…you could potentially gets wild reels 2, 3 and 4 off a three scatter trigger.