Merge pull request #58 from martinaLopez/master

Added bosses, minions and logic to level 1 and level 4. Fixed _init_ in Enemy and Player.
Merge pull request #60 from dgalaktionov/master

The game is complete now
Improved raytracing implementation.
In my pc the FPS never drops even if all enemies on the scene are chasing you.
Now enemies flash in red when you hit them.