Tomy Kongman is one of those games that cashed in on the Donkey Kong craze. This game had the most simplest of faults in that it didn't do anything when you inserted a battery but fixing that was a whole different matter!
If you need a replacement motor for your Kongman or Kongman like game, the good news is that it uses one of the most common DC motors. Search eBay or Amazon for miniture small round motor 1.5v - 3v for models, robotics, etc but first check to see if you have any power going to it.
Like I mention in the video, this was the original but their are lots of variants of this game to which, all the steps carried out in this video should also apply as these are also all made by tomy, just different graphics and platic colours. The variants are:
Sonic the Hedgehog mountain quest
Search The Haunted House
Don't bite the pavement
Finally if your only problem is that you're missing your balls, give me a thumbs up as the size is 11mm or 7/16" so you can buy a pack of ten for the same price most eBay sellers are selling two for.
Music by Matt Hipp - Alien Wheat Field - https://thmatc.co/?l=F504DBF0