I think all the features you have mentioned exist in some form already. The tag "animal" can be added to any puzzle that has animals in it, but seems pretty broad. I would bet a huge portion of the puzzles include animals of some sort. So we will probably keep it as tags for now. We have the ability to auto-add tags or switch tags. I haven't filled in many of those switch out values so far. You can search by number of pieces. Look at the top of the search page. It defaults to ANY but you can pick a range of pieces. You can also filter by distance and other things at the top. You can also see if a puzzle has missing pieces. Take a look at this page for details on the missing pieces. https://puzzleswaps.com/blog/e23/missing-pieces-are-now-tracked/