Which RTP version runs in the game rules?
Three SCATTER symbols start 15 free spins, four start 20 and five start 25. How often those symbols land is not known in advance, and no figure on this page gives that rate. Each session is random, so a single one can end with a long bonus run or with none at all, whatever the RTP of 96.50% says about the long run.
96.50% is the RTP listed for Big Bass Halloween 3 in this page's tables. The version running in a given lobby is shown only in the game rules, so check there before you play. The number in the table is the long-run return on A$100 staked, not a promise for one session.
x5,000 is the largest win this slot can pay, which is A$5,000 at the example top bet of A$1. That ceiling is reached very rarely, and no spin can be counted on to get there. The cap is a multiple of the bet, so the money amount grows or shrinks with the stake you choose.