Read the rules before you count on a win
Before you set a budget for Retro Sweets, know that how often the bonus round comes is not known in advance. The result of one session is random whatever the RTP shown, so a high RTP does not mean a short wait or a win.
Choosing a version of Retro Sweets means looking up its RTP first. That detail is shown only in the game rules, so read them before your first spin, and treat the rules as the final word on the version in play.
Before you raise your stake on Retro Sweets, keep the ceiling in view. The maximum win is a ceiling reached very rarely, and it is a multiple of your bet, so it grows only when the stake does.