Note: This can be scaled up as you require.

This is just a simple puzzle I made - mainly for testing my limited knowledge of Fusion 360, but it turned out so well I thought I might as well share.

The puzzle pieces are in one STL file, and unfortunately cannot be moved around but it does make scaling up much easier. I've also added the Fusion file so you can mess about with the pieces and resave as you wish.

I would probably recommend a raft for the pieces unless you have confidence in your adhesion :P

Pieces fit together perfectly, with no wiggle room. There are probably a few correct solutions, I didn't meticulously measure each individual piece to make sure they could only fit in one place, but it should be a little distraction - especially for the younger members of the family.