There is alot to do in Hyrule Market. Firstly, you have one of the easiest mini games in the
whole game, The Treasure Chest Game. Also, there
are three pieces of heart (to the best of
my knowledge) to be earnt. Also, you have the
Target Practice mini-game, and Bombchu Bowling, quite easily one of the most annoying
mini-games in the whole of Hyrule, purely because of the randomness of it's prizes, sometimes
it can take quite some time to get what you want. And, last but not least, Hyrule Market is the
central location of Young Link's Trading Sequence, which
should be completed before proceeding to Adult.