I have reworked the wall collision detection a bit more to checking only 4 points instead of 8.  This makes some parts more accurate and some parts less accurate but should make collision detection faster overall.  In working on things like collision I've been trying to push more code down into the CActor base class for collisions between actors or putting all the world collision code in the CMapLayer classes to try to limit the amount of over lap though subclasses of CActor can always override the actor/actor collision by overriding the Update method.

Adding in the concept of health and damage into the game might be the next big part I need to work on.  Along with this I would also likely implement the initial hud so there would be some kind of indication that you were getting hit.  Hits are currently registered but mostly discarded since there is no health to check things against. When I add in health this might also require rewriting some of my functions that are triggered upon collisions (like when an Actor gets hit with a bullet).