I originally wrote this to learn Swift 1.x. I've since updated and cleaned it up for Swift 2.x and Xcode 7.
The code and architecture based on the original Objective-C SpriteKit Physics Collisions sample from Apple.
Some of the differences in this version from the Apple code, includes breaking out the constants into a seperate swift file, as well as a few other minor organizational changes.
- w or forward arrow : accelerate forward
- a or left arrow : turn left
- d or right arrow : turn right
- s or back arrow : accelerate backwards
- space bar : fire a missile
- r : reset the simulation