Fishin' Frenzy Megaways runs on 6 reels and pays up to 15,625 ways, with a default RTP of 96.10% and a top prize of 10,000x your stake. Reel Time Gaming built the maths and Blueprint Gaming brought it online in April 2019, and it quickly became the most-played sequel in the whole series. Volatility sits at medium, so it isn't a punishing game, though the ways engine does make sessions swingier than the 10-line original.
The hook you already know is still here. During free spins the Fisherman Wild lands, collects every cash-value fish on screen, and pays their combined total. What's new is the multiplier: in this version each collected fish can be boosted by up to x5, which is where the higher ceiling comes from.
One caveat before you play for real money. That 96.10% figure is the studio default, and operators are free to run lower official builds. Reported live RTP for this game usually falls between 95.02% and 95.50%, so the paytable is the only reliable way to confirm which version you're on.