added bullet rotate.
added support for rotating and scaling bullet, emitting in front of entity
support for rotating entity
fixed stopping behavior, changed bullet type
support for rotate and scale
added doors, random enemy spawning, character death, advancing stages, resetting. player melee attack
animate bullets
animate bullets
map object by name
door objects
enemy types
dying, flcikering, restoring HP
check if there are remaining enemies, moved move logic from physics engine to move method
set up as enemy projectiles
melee attack for the player
melee attack
moved move logic out of physics engine
extra maps, enemy overlays, sprites