     func swipeUpGesture(recognizer: UIGestureRecognizer) {
         if (!_gameover) {
             if (birdNode.mode == .Flying) {
-                birdNode.physicsBody?.applyImpulse(CGVectorMake(1.5, 20.0))
+                birdNode.physicsBody?.applyImpulse(CGVectorMake(2.5, 20.0))
             }
         }
     }

        if (!_gameover) {
            if (birdNode.mode == .Flying) {
                birdNode.mode = .Landing
                birdNode.physicsBody?.velocity = CGVector(dx:0.0, dy:0.0)
                birdNode.physicsBody?.applyImpulse(CGVector(dx: 0.05, dy: 0.0))
                birdNode.physicsBody?.affectedByGravity = true
            }
        }
    }


import SpriteKit
import AVFoundation
import CoreMotion

private let spriteLineCategory:UInt32 = 0x1 << 1;

