I remember LOVING this game as a kid. It was my first open world game, and the idea of being able to fly through Gotham City and do stuff just absolutely blew my mind. I don't actually remember if there was much to do in the open world, or if it was more a cover for the actual missions, but I adored every second playing this game.
This was also the first LEGO game where they tried their hand at voice acting, and while I thought it was super cool then, I have mixed feelings about it now. Before the voice acting, LEGO games had this signature parody humor that they had to pull off without words, and I honestly think it payed off, thought that seemed to diminish after the games started having voice acting. Just something I wanted to mention.