The provider publishes a return to player of 96.5% for Gates of Olympus. That is a long-run average across an enormous number of spins, not a target for a session. Some sources carry lower numbers for the same title, which is itself a reason to treat any single RTP figure as a published claim rather than a promise. A session of a few hundred spins can return far more or far less than 96.5%, and the high volatility setting is what makes that spread wide.
Read next to the shortlist, the figure sits at the top: Big Bamboo at 96.13%, Starburst at 96.08%, Wolf Gold at 96.01%, Queen of the Nile at 95.98% and Pompeii at 95.96% are all lower. Half a percentage point of return sounds small until it is applied to volume, which is exactly why the number matters more to a regular player than to a one-off spin.