One thing that annoys me is the escape tunnel, how did she get it built without the organizors of the event knowing about it? And if there was an escape tunnel all along, then no-one needed to die. In fact, the presence of the escape tunnel means that no-one supervizes this game at all, the Goverment get a bunch of kids to kill each other and then clean it up afterwards, but they don't watch the actual killing take place, which just raises more questions about why they do it in the first place as all they seem to be doing is creating more un-needed work and expense for themselves.
It seems to me that the Author wanted to write a high/middle school drama, but was asked to turn it into a killing game manga