The "introduction" if you will is pretty much done, although the character can be completely OP in combat, but I'll deal that after the bugfixing I need to do
I'm now working on a) the bugs and b) the main open part (at least for now).
Some more info: The game is based in a school, just because most of my zombie plans are based around school (I need a contingency plan in the case of an apocalypse there)
But in the future I may expand further. The more open part is that you can move into any room in the school you want, albeit with random encounters, and find weapons etc.)