what is wrong with my code

import random
words=['apples','banana','grapes','orange','lemon','melon','strawberry']
while True:
  start=input("Press enter/return to play or q to quit  ")

  if start.lower()=='q':
    break
  secret_word=random.choice(words)
  good_guesses=[]
  bad_guesses=[]
  while len(bad_guesses)<7 and len(good_guesses)!=len(list(secret_word)):
    for letter in secret_word :
      if letter in good_guesses:
        print(letter, end='')
      else:
        print('_', end='')

    print('')
    print("strikes : {}/7".format(len(bad_guesses))

    guess=input("guess a letter :").lower()
    if len(guess)!=1;
          print("you can guess only single letters ")
          continue
    elif guess in bad_guesses or guess in good_guesses:
          print("you already guessd that letter ")
          continue
    elif not guess.isaplha():
          print("you can only guess alhabets ")
          continue
    if guess in secret_word :
          good_guesses.append(guess)
          if len(good_guesses)==len(list(secret_word)):
              print("you win the word was {} ".format(secret_word))
              break
    else:
          bad_guesses.append(guess)
  else:
          print("you lose my word was {} ".format(secret_word))