Er… unplayable?
Can’t Find URL: HauntedGarden: . Invalidating and reverting to Default URL. Travel Failure: [InvalidURL]: Invalid URL: /Game/MAINMENU
The cook manifest only includes HectorTheSpector/Content/MAINMENU.umap and Engine/Content/Maps/Entry.umap
So I think you forgot to build it with the level that the game was actually on.
Is there a particular reason you chose Unreal? It seems like overkill for this type of game, but no shade if it was just a way to experiment.