This is the basic structure of most BlitzMax games.
'This is what a comment looks like
AppTitle$ = "Application Name" 'Set the title of the window
Graphics 640,480 'Set the graphics window to be 640x480
While Not KeyDown(Key_ESCAPE) Or AppTerminate()
Cls
SetColor 0,0,255 'Set the fill color of the rectangle
DrawRect 100,100,5,10 'Draw a rectangle at x=100 y=100 that is 5x10
Flip
Wend
Ghost