It’s definitely possible if the horse has good balance! My gelding who is 16.2 previously done mounted games in his old home with some younger riders, his turns weren’t quite as tight as the ponies but he sure tried!
My horse was a 17-hand- horse and I could do it! So there’s no reason you can’t!
Of course you can! It might be hard if the game requires lots of mounting and dismounting, but otherwise there is no reason not to
You could but it may be harder then riding a smaller pony! :)