If the developer took care of their tagging situation this should help:
I have created a filter based on what we know right now (assuming it was 3D because of the first person, it was free or pay-what-you-want, or otherwise it would be in your library), but it still spits out 255 results. If you happened to have played it on Mac 57 results or 50 results on Linux. Or 201 results on Windows.
Maybe have a look at the Tag Directory yourself and see what else seems fitting.
Unless somebody who played that game as well happens to see this thread, your best chance will be: Going though those 200-ish cover images and hope the one the developer chose was representative of their game…