The Zeus slot features a free spin bonus triggered by getting 3 or more of the blue lightening symbols anywhere in view. If you get 3 of them, you get 10 spins, 4 is for 25 spins and get all 5 and you're in for a real serious payday - 100 free spins! The Zeus slot also features stacked Zeus symbols - this is what you really want for big payouts and when you get the freespin bonus not only does Zeus add more of these to the reels, but it also stacks the Wild symbols.
The Zeus slot is a really good video slot and I'd urge you to at least try it out. You'll see what I mean I think. Watch out for Zeus II when it comes online too - one of WMS's very popular land-based "Super Respin slots" (check out the Griffins Gate slot to see), and very distinctive. If you go to Vegas, you will hear these long before you see themf! Check out the other WMS slots that are also now available to play online, most notably the Spinning Streak and Hot Hot Penny games. If you don't know them already then you'll probably be very pleasantly surprised by some of them.