Need Puzzle Idea

How about a rotating picture one similar to the ones used in Assassins Creed 2? A series of concentric rings that rotate to form a picture. Do three or four successive ones that get harder as you go, more confusing pictures or rings that move together (A moves by itself, B moves by itself, A & C move together sort of thing) making it harder to match. You give them the picture to rotate and as each one is solved the floor opens to reveal the next

I also run a teens group at a library and the one thing I’ve realised is I can steal puzzles and even entire plots from films, tv, and games because they’ve not seen as much as I have so I tend to recycle other people’s ideas a lot 

What if it works like a combination lock and it has a pointer at numbers ringing the wall? Maybe there is a book they find somewhere that has 3 page numbers circled or clearly dog eared with a scribbed note next to each number with 1R, 2L, or 3R for 1st # turn right, 2nd # turn left...ect, or something that like and the floor is controlled with the special something in the center of the room. They can get hints if they super stumped with investigation checks or the special puzzle box in the center is somewhat shaped liked a combination lock.

You could also make two rotating disks and fix the on top of each other with the bottom disk being bigger than the inner one. Then you add symbols of dragon themed stuff around the outer edges of both. Then give them a riddle that tells them how to align the two disks. Maybe it is a multi step process. Like three alignments done correctly solve the riddle. And just for fun add a "bad outcome" combination that should not be locked in at all or some enemies come and attack them! :)