'seturn' outside function问题

问题遇到的现象和发生背景

用python编写pygame代码时发生 'seturn' outside function的错误

用代码块功能插入代码，请勿粘贴截图

def runGame():
    #setup veriables for the start of the game
    board = getBlankBoard()
    lastMoveDownTime = time.time()
    lastMoveSidewaysTime = time.time()
    lastFallTime = time.time()
    movingDown = False #noet: there is no movingUp variable
    movingLeft = False
    movingRight = False
    score = 0
    level,fallFreq = calculateLevelAndFallFreq(score)

    fallingPiece = getNewPiece()
    nextPiece = getNewPiece()

while True:#game loop
    if fallingPiece == None:
        #No falling piece in play,so start a new piece at the top
        fallingPiece = nextPiece
        nextPiece = getNewPiece()
        lastfallTime = time.time()#reset lastFallTime
        if not isValidPosition(board,fallingPiece):
               return
    checkForQuit()

运行结果及报错内容

'return' outside function
return中的r被框红

我的解答思路和尝试过的方法

搜百度

我想要达到的结果

成功运行