There are obvious crossovers in the gaming world (Fortnite plus any global media franchise) and less unpredictable ones; Return to Castle Monkey Ball belongs to the latter category as what the title suggests is a mixture of the fps Wolfenstein 3D and the platform game Super Monkey Ball!
You can check out a trailer for Return to Caslte Monkey Ball below, and play it directly in the browser via Itch.io. In total, there are eight procedurally generated levels, where you must pick up bananas and treasures to maximize your points, and defeat guards for time bonuses. And you probably do best in trying Return to Castle Monkey Ball right now, as this type of project does not tend to be very long lasting on the internet.
Here is the launch trailer for Return to Castle Monkey Ball.