REBOL [title: "Space Invaders"]

    alien1:  load to-binary decompress 64#{
    eJx9UzFLQzEQjijUOognHTIVhCd0cXJ1kLe3g7SbFKcsWQoWZ7MFhNKxg0PpH3Cx
    WbKUqpPoUNcOPim1Q+kPkCJekvf0NTx7cLl7d8l33+XywvL+FrFyhVpCPUY9QN0g
    LnG7ScjjrtM98iedToeM3kbW7/f71k4/p6R+USe9Xo/UqjUbi94jMhgMrL/8XpLm
    ZZP4spPyzxVTT35MM2Zir4vFYu4dM7GP2M483Fa8f8w0O/Vy24yzo8RXipfJmdb8
    kJxwrdJ7K4gxiSs7/09czYpdW6vcsI+AtrEKQ7ScDPlLHO/aNQ8huzaVeSDaHrNi
    3IlBjDI6mqVsWvIA0E5ZJ2OtlUIuAKHmqoS5kHOt9UPMP0sm3TU5PHdHQVIZMs3v
    qZTPmrMAQAj6ZXOSUtkwPKRwloKQNlexCDOvR4fpclGq76KNzC2mQPiG681i5gAw
    ZusVJEAh5JojBzrEGQYC2dncuh7+y83d7ASVAu8MpAQqkT9+3Gg3Q+wHI2AZSAFm
    1+99FzMQkzllVUxeTFUrc4vC4Q4VV4wlLyaerjD1XPe+tLxK8SNbqTrJOIf/Bd4X
    V+VU7AfjSm0ZEgQAAA==
    }
    ship1: load to-binary decompress 64#{
    eJx1Us9L3EAU/rTbMdHE9VlYukSQFhUpvXjQXrfizR8XkYAnt0oQVsTLGlgEFdSL
    l3jqpXgre6sEJAgDsidPIul/sHjopeIfILj0JdnV3ez0y7zJzLx533vvY2YXhzOI
    scs2yfaF7QNbDxLHjzfAu4HEhpKryAgDfccC4rfAws0IjF/96HsWyH7XMNXIon9Z
    QJvWsNQw8XZP4NPlKD73Whi/HcZO4z207fv7jyo8/jk4r1TdFQXcSrV+flEtq3x2
    5amuB44lyU+BpHRKHq4dKXnZCbLkxl9kOF5BarPVDFWyBAWcEAVFsjrhENGmhyPK
    UXe+XNHf9HqZW9GgyzUUoloqXcXE1wv6iSTHohSkQ8yJQ5l2RCiSvPIGbaVkTFuu
    Ge5/erfdurb+wM3ETZHPyjaX5NzNHPATOHMsn894sMZJWX4uH78OYSvTrUU+paI2
    q8nQl5JHMFaSOZLBbHPnoR2ndHUa5NtPwubfFKziT1YqRDdY2VV3JckT3X2ZIlwW
    KQjmUxGhGQ0Ecm5OlhBvUsSi/NpXmjLRoFx4YWuL0789fN24m+jsK2x+wGE+JjLR
    DePiqdbKZqZojf1qLZ2ptdO3ZrxXwjCODzuThK3Af4EF8jYSBAAA
    }
    alien-fire: load to-binary decompress 64#{
    eJxz8o1jZACDMiDWAGI+IJYFYkYGFrD4CyAW5oZgAYhSBhZmFoaWphaG48eOMwQF
    BDFoaGgwPH36lGHZsmUM4uLiDFk5WQyzZs1iuHHzBsOfv38Ydu7cyWBhZsFQXlrO
    EBEVATTBaWlolAoDA/vp3bt37wHyZwPpTUCaedqpUBWGS6HLMj8AedpA0Z1QGqTK
    KXrNtCdgF/BLtrCD6GywOAPDabA6BobCTAMwXTfzFMh8uM7ZUBpi/p3QZdMMwLp2
    796GbH7omrR2sH6Omc+h5m4C09pQuiKzHWp+O1R+D1QeQjstPQINIwag+wBUhlwj
    XgEAAA==
    }
    ship-fire: load to-binary decompress 64#{
    eJxz8t3FAAFlQKwBxOxALAjEjAwsYHEXIBbmhmABqFo2FhYG9l4eBvajbAwKSTIM
    /H8FGFjUOBg4tnEyGP1VYWAXZWOwadNg4KhiYdA5JMLAacbJIHNLhUFnkgiDIpMg
    2IyDd2UYVMqdGNLLyxoOz7RpCJ5p2pDi4sYAwlFpSz+AcEoJkF8O5KstZWhUkvig
    4uLEoAIUO7f7zQcA8m8lvboAAAA=
    }
    the-score: 0  
    speed: 0
    lowest: 0
    random/seed now
    b: ['image 300x400 ship1]
    for row 60 220 40 [
        for column 20 380 60 [
            pos: to-pair rejoin [column "x" row]
            append b reduce ['image pos alien1]
        ]
    ]
    view center-face layout/tight [
        scrn: box black 600x440 effect [draw b] rate 0 feel [
            engage: func [f a e] [
                if a = 'key [
                    if e/key = 'right [
                        b/2: b/2 + 5x0
                    ]
                    if e/key = 'left [
                        b/2: b/2 - 5x0
                    ]
                    if e/key = 'up [
                        if not find b ship-fire [
                            fire-pos: b/2 + 25x-20
                            append b reduce ['image fire-pos ship-fire]
                        ]
                    ]
                    show scrn
                ]
                if a = 'time [
                    ; fire a bullet at random times from random aliens:
                    if (random 10) > 1 [ ; increase "> x" value for more fire
                        rand-alien: (random (((length? b) - 3) / 3)) * 3 - 1
                        ; only fire from bottom row - 
                        ; determine lowest alien coordinate:
                        for q 1 (length? b) 1 [
                            if (
                                ((type? (pick b (q + 1))) = pair!) and 
                                ((pick b (q + 2)) = alien1)
                            ) [
                                if ((second (pick b rand-alien)) > lowest) [
                                    lowest: second (pick b rand-alien)
                                ]
                            ]
                        ]
                        fire-pos: ((pick b rand-alien) + 25x70)
                        if (second fire-pos) > lowest [
;print [b/62 "  " lowest "  " fire-pos]
                            append b reduce ['image fire-pos alien-fire]
                        ]
                    ]
                    for i 1 (length? b) 1 [
                        ; move ship fire:
                        if ((pick b i) = ship-fire) [
                            either ((second (pick b (i - 1))) < -10) [
                                ; if at top of screen, remove:
                                remove/part at b (i - 2) 3
                            ] [
                                ; otherwise, move up:
                                do compose [b/(i - 1): b/(i - 1) - 0x8]
                            ]
                        ]
                        ; move ships:
                        if ((pick b i) = alien1) [
                            either ((second (pick b (i - 1))) > 400) [
                                ; if at bottom of screen, end game:
                                alert "Game Over!" quit
                            ] [
                                ; otherwise, move:
                                ; move left:
                                ; move right:
                                ; move down:
                                do compose [b/(i - 1): b/(i - 1) + 1x0]
                            ]
                        ]
                        ; move alien fire:
                        if ((pick b i) = alien-fire) [
                            either ((second (pick b (i - 1))) > 400) [
                                ; if at bottom of screen, remove:
                                remove/part at b (i - 2) 3
                            ] [
                                ; otherwise, move down:
                                do compose [b/(i - 1): b/(i - 1) + 0x1]
                            ]
                        ]
                    ]
                    the-score: the-score + 1
                    score/text: to-string the-score
                    show scrn
                ]
            ]
        ]
        origin across at 20x5 h2 white "Score:" 
        score: h2 white bold "000000"
        do [focus scrn]
    ]




{


                                do compose [
                                    b/(index - 1): b/(index - 1) + 0x1
                                ]
                                ; old-pos: pick b (index - 1)
                                ; remove at b (index - 1)
                                ; insert at b (index - 1) (old-pos + 0x1)
                                ; change at b (index - 1) ((pick b (index - 1)) + 0x1)





print "yes"
                    foreach item b [
print item
                        if item = ship-fire [print back b]
                    ]





{
                    for item 1 (length? b) 1 [
print compose [b/(item)]
                        if ((pick b item) = ship-fire) [
                            do compose [
                                b/(item - 1): b/(item - 1) - 0x5
                            ]
                        ]
                    ]

}


{

                        delay: delay + 1
                        ; loop speed # of times before moving aliens
                        ; (reduce speed value to move aliens faster):
                        if delay = speed [delay: 0]
                        ; if delay < 1 [(move aliens)]

                    ]

}
                    
 
{

                    new-b: copy []
                    foreach item b [
                        either all [
                            ((type? item) = pair!) 
                            ((length? new-b) > 3)
                        ] [ 
                            append new-b (item + 0x5) 
                        ] [
                            append new-b item
                        ]
                        coord: first back back (tail new-b)
                        if ((type? coord) = pair!) [
                            if ((second coord) < -60) [
                                remove back tail new-b
                                remove back tail new-b
                                remove back tail new-b
                            ]
                        ]
                    ]
}


                    if (length? new-b) < 4 [
                        alert "You killed all the aliens!"
                    ]

{
                    b: copy new-b

                    collision-b: remove/part (copy b) 3
                    foreach item collision-b [
                        if (type? item) = pair! [
                            if all [
                              ((item/1 - b/2/1) < 15)
                              ((item/1 - b/2/1) > -40)
                              ((b/2/2 - item/2) < 30)
                              ((b/2/2 - item/2) > 5)
                            ] [
                                alert "Ouch - you hit a tree!"
                                alert rejoin ["Final Score: " the-score]
                                quit
                            ]
                        ]
                    ]

}




}