Funny 4-Bicycle

Now you've got a mission! It is to deliver your mother's cookie to grandma! But grandmother's house, is so far away... about 500KM!! Furthermore, you have not a penny, so you have to go by bike! Oh, my God! Fortunately, you have a special bike built for four, and friends to travel with. But They are mischievous boys... they sometimes play tricks, especially if you are not watching them! lol! You have to punish them, and upgrade your bike. So then you can get to the grandmother's house!