My sons wanted a case too I tweaked my other case model make this simple case for a Samsung Galaxy A03s Phone. It has corner bumpers and fits quite well. It isn't the prettiest thing on earth, so feel free to remix some decoration onto the back or do with it what ever you like. I have included the Fusion360 archive file if you want to play with the CAD file.

I printed in TPU with a reduced bed temperature (35C). When I printed at the recommended temperature it adhered so well it tore off the PEI covering and ruined one side of the print bed.