The Cleopatra bonus round
Getting three or more Sphinx scatter symbols triggers the Cleopatra bonus round, where you are awarded 15 free spins with all wins multiplied by three. The bonus can be retriggered by getting three or more Sphinx symbols in a bonus round spin, which gives you an additional 15 free spins. The bonus rounds, with the 3x mulitplier for all wins, is where you typically will win the larger payouts.

Cleopatra II slots
Cleopatra II is the follow up game to the original Cleopatra slot machine, and the main difference between the two games is the bonus round. With Cleopatra II, getting three or more Sphinx symbols triggers the bonus round where you choose one of three icons to discover how many free spins you will receive. With each free spin, a multiplier increases by one: a 1x multiplier on the first spin, 2x on the second, 3x on the third... up to a 15x multiplier on the 15th spin, which multiplies the wins by that amount. If you are lucky enough to retrigger the bonus round, you can receive up to 50 free spins with a 50x multiplier on the 50th spin, creating the potential for some very large payouts!

Overall, the Cleopatra slot machines are a good basic slot machine to play with some potential for large payouts in the bonus rounds. I personally have never done very well with this game, so I don't play it much myself, but it seems to be a hit with the older ladies.