To be honest, although I know the X-Men slot is pretty popular, it's not one that has ever really grabbed me in the way some other Marvel slots like Fantastic 4 or the volatile Iron Man 2 slot have. Maybe it's just that I've never had anything decent from it or maybe it's because I never really grew up with the X-Men brand, not sure.
As far as the Playtech Marvel games go though it's once again original. You'll notice immediately that it doesn't use the tried-and-trusted J-Q-K symbols and instead plumps for characters in every position. The X-Men logo itself is the free spin trigger and, as with most other slots on freeslots247.net, the free spins is where the action's at!
X-Men has this thing called 'unlimited free spins'. The reality is of course that they aren't unlimited - they just have the potential to be unlimited. You' have more chance of going to the moon on an inflatable rubber duck than you do of getting unlimited spins on the X-Men slot but at least it means you usually get a decent number.
The free spin bonus does this thing where it flicks between two modes - a bit like the Kong slot only in X-men it only happens in the feature. One mode has unlimited spins, one has a finite number and once the latter runs down you are done. I'll let you figure it out - it's decent enough but like I say, I've never won a biggie from it.