The beauty of playing futsal, which is extremely popular in Brazil, is unlike indoor soccer, there are no walls to play the ball off of. In futsal you have to control the ball and keep the ball in bounds just like in outdoor soccer. Christian Pulisic played futsal growing up and he's said it improved his technical ability and skills in tight spaces. In fact, his dad had to start a futsal league in his area just so Pulisic could play it since they didn't have one.
And, in futsal you use a different kind of ball, one that doesn't bounce as much and is a bit smaller. Overall, futsal is a great way to improve your touch and skill on the ball during the off-season.
Check out the awesome futsal (indoor-soccer) skills from Ronaldinho in the video below. While this is an older and retired Ronaldinho, you can still see he's got skills on the ball.