; Strengths
Const Gravity = 1
Const Thrust  = 3

; Ship position
Local X
Local Y

; Ship image handle
Local Image

; Initial X coordinate (middle of screen width)
X = 320
; Initial Y coordinate (bottom of screen)
Y = 480

Graphics 640 , 480

Image = LoadImage ( "Ship Pre Final.PNG" )
MidHandle Image

; Now drawing to the invisible screen
SetBuffer BackBuffer ()

Repeat

    ; Space is being held down
    If KeyDown ( 57 )  ; Space
        ; Lift off!
        Y = Y - Thrust
    End If

    ; Gravity is always in effect
    Y = Y + Gravity

    ; Prevent ship from falling through the bottom
    If Y > 480 Then Y = 480

    ; Display the ship
    DrawImage Image , X , Y

    ; Flip the invisible with the visible screen
    Flip
    ; Clear the invisible screen
    Cls

Until KeyHit ( 1 )  ; Escape

; Manual cleanup (not required)
FreeImage Image

End