Made graphics better
Added bullet sprite
Put player back to original layer
Made css background black
made gunshot not stop when bullet disappears
added score counter. points for time and alien kills
points awarded on alien kill, not bullet hitting alien
created 2 groups. sprites in Play.js integrated
Made aliens bigger
improved AI and other alien related things
made spawning
added reloading warning
merged with alien AI changes
changed spawn timer to count instead of score
Make collisions work better
made collision area smaller and made spawning independent of score
dead aliens don't kill you and shooting aliens gives fewer points
collision with gun also included
collision with gun smaller circle
sprite layers are now background->player->aliens->shadows->hud