If You Go...
Generally the performances last about two hours. Usually, there is no seating, but that varies with the arena. Photography is allowed and I recommend you bring a camera. There is a souvenir stand, but they seem only to take cash. Oh and if you plan to stand in the danger zone, wear old clothes.
Kaiju Big Battel is not very intellectual, however it is a delightfully absurd. If you have a chance to see it, go. It is something to be experienced for the benefit of your inner geek. Remember, while danger can happen, fun will happen!
For more information and general weirdness, check out their website, http://www.kaiju.com.