Performance update

Improved CPU performance in level 4 and 5 ; Some critical improvements have been made to the way we check how many enemies remain. This was not properly implemented, and the game had to constantly cycle through all game objects at regular intervals, saturating the CPU. This is critical in level 4, because it has 50% more actors than other levels on average. We implemented an "enemy manager", which keeps track of the enemies spawned, and is much more optimized. Please let us know if you had performance drops in level 4 or 5 and if this has resolved them. Thank you, Mantarayg72, Ocelot, and talonus, for reporting this issue, and we hope it resolves the problem. - Improved GPU performance in level 5 Some shaders have been optimized, which should help with framerate issues in level 5 on lower hardware. - More fixing in level 4 The arachnoid implementation has been revisited, in yet another attempt to fix the occasional bug where the Arachnoid would freeze after its intro animation. This should fix the problem for good!