You'll notice behind where Batman is in the picture, there is a Technic pin. If you put Batman in front of it and move the pin, he can "jump" forward. The clear piece in the front of the picture is the "super jumper" so Superman can "leap" at Batman. I noticed this feature last year, but maybe it has been around for a while. Either way, it doesn't do much for me. Maybe for the younger audience it has an appeal. I tried it and Superman doesn't jump really well. I recommend using your imagination and picking up Superman with your hand to pretend he is flying at Batman. That way you can make a fun swooping noise with your mouth too. Back to the intro of this post... why are they fighting anyways? The joy of LEGO... I can always turn this set into a cafe where Superman and Batman meet up for some coffee and donuts.
So my final opinion on this set. Get this if you want the minifigures. The build itself is rather simple and it is geared towards kids as opposed to an old kid like me. The parts can be found elsewhere and if you want the Bat Signal, I'm sure you can find it online. The minifigures are pretty good though Batman and Superman have come in various forms and these are pretty impressive. Also, watch for chances to catch the set on sale.
The 2 heroes from this set are below if you are interested in them as well as some other versions for sale in the store on BrickLink.