Games (probably any submissions??) which are removed but then re-added nevertheless do not re-add into whatever database Newgrounds uses for search.
So if a game is removed but then later added back again by the author, it will not be searchable on Newgrounds nor show up in any of the usual places but you'd need the exact URL to play it.
Here is an example https://www.newgrounds.com/portal/view/713803
You can only get there by that exact link or by viewing the medals of someone who has at least one medal in that game and clicking the link there. Try searching for "fidget spinner" or "fidget spinner tycoon" and it doesn't show up in any of the results.
