Strange. When I published it, I couldn't find it either. I had assumed I fixed that when I updated it. But I talked with a friend and he was able to locate the game with no problems. The game runs fine in my own files, but I cannot access Explore! I tried clicking on check for updates, but it slowly increased in percentage, then later crashed. Now I can't access Explore. This is a problem.
I've found there is a difference between running the game from your own files and running the game in 'Explore'. So as a recommendation whenever you publish a game always test it in the 'Explore' section to make sure it plays correctly.
The 'Explore' section crashing whilst 'Checking for updates' also happened to me so I had no access to any 'Explore' games. However with help from TingThing I managed to recreate the 'Explore' section.
On your PC, in the run edit box type %LOCALAPPDATA% and press <enter>
This will bring up File Explorer.
Go to the PlatformBuilder folder
within this folder go into the Explore sub-folder
you should see a lot of game and sandbox sub-folders etc...
optional step: backup all these files elsewhere
then delete all these files. This should clean the Explore section and next time you run Platform Builder try 'Check for updates' again and you should be able to download the list successfully.