So, with the public release of Metal And Magic Beta 6.5b, you can choose either a Defense or an Arena game type. This poses a new challenge when it comes to balance, since in fact all Guns, Shots, and Items must be balanced for both styles of gameplay.
I have already made multiple adjustments to the duration of disabling Shots against heroes, as well as modified Item/Set abilities.
But, me and my testers will certainly miss some, since even we can't test every item build against all others. So if you find yourself going "WTF!" in an Arena game, please post it here so that I know.