Where a return-to-player percentage is published for a pokie, it is a long-run average across millions of spins. It is not a target for a session, not a promise about your balance after an hour, and not something a betting pattern can influence. A game with a published return still loses money for most players on most days, because the average is exactly that.
Happy Prosperous does not have a published return figure on this page at all, which is the more important point. Volatility, grid size, payline count, minimum bet, provider and release year are all knowable. Whether the game is generous or tight over time is not, from the figures available here. Spin only with money you can afford to lose.