Plan your session around what stays random
Scatter symbols land anywhere on the 6x5 grid, and four or more of them open the Free Spins round. How often that happens is not known in advance, because each spin is random. The RTP tells you the return over a very large number of bets, not the outcome of one session, so a session can end above or below the stake whatever the RTP shows.
Each spin settles against one of two RTP versions, and the two differ only slightly in return. The figures table on this page shows what each version returns in money. Which version runs here is shown only in the game rules, so read that section before you choose a stake.
Tumbles, multiplier orbs and the Total Multiplier can lift a win, yet the maximum win is a ceiling reached very rarely. It is a multiple of the bet, so a bigger stake raises the money value of that ceiling. No one can say in advance whether a session will come near it.