The spectacle is a mass sensory experience. First it's all in 3D (which here is quite fun). Second, there are air & water effects e.g. when spidey spins a web or the hulk sneezes, we get jets of air & water squirted at us! When Wolverine slashes, we feel a jab in the back!
As it's 3D action we get lots of "pointy pointy" as things come flying at the screen, but it's a short and it's trying to cram action in as much as possible.
Most people in the small auditorium were laughing and shrieking with the action so they were very much enjoying it. It's a nice break from the usual cinema fair, and if you're in London then this is something you will enjoy for the experience, kids in particular will lap it up.