Code Sketch

def p = Picture {
    val pos = position
    right()
    forward(50)
    left()
    arc(50, 45)
    moveTo(pos)
}

val gg = fillColor(green) -> p
val bg1 = trans(200, 0) * fillColor(black) -> p
val bg2 = trans(-200, 0) * fillColor(black) -> p

clear()
invisible()
draw(gg, bg1, bg2)
drawStage(pink)

def badBehavior(me: Picture, bvec: Vector2D) {
    bvec.rotate(randomDouble(10)-5)
    me.transv(bvec)
    if (me.collidesWith(stage)) {
        bounceVecOffStage(bvec, me) 
        me.transv(bvec)
    }
}

val speed = 1.5
val sf = 1.5

val bg1vec = Vector2D(0, speed)
bg1.act { me => 
    badBehavior(me, bg1vec)
}

val bg2vec = Vector2D(speed, 0)
bg2.act { me => 
    badBehavior(me, bg2vec)
}

gg.act { me => 
    if (isKeyPressed(Kc.VK_RIGHT)) {
        me.translate(speed * sf, 0)
    }
    if (isKeyPressed(Kc.VK_LEFT)) {
        me.translate(-speed * sf, 0)
    }
    if (isKeyPressed(Kc.VK_UP)) {
        me.translate(0, speed * sf)
    }
    if (isKeyPressed(Kc.VK_DOWN)) {
        me.translate(0, -speed * sf)
    }
}

val baddys = List(bg1, bg2)
gg.act { me => 
    if (me.collision(baddys).isDefined) {
        stopAnimation()
        me.setFillColor(red)
        write("You Lost")
    }
}
activateCanvas()