Have you tried adding a "Museum" tag to your game? "Slime" has been in mine since early July but I still have this problem, not sure if that even influences search results.
Viewing post in My game isn't showing up on search or new.
Adding tags to a project don't alter how they appear on the search results. Tags are for classification and so you'll need to go to the respective tag page on our browse pages to filter by those projects. Search is currently set up to look for title matches (or match on the short description), but if you type in an approved tag it will suggest that page as well.