This is an opera performed by marionettes, with recorded music and libretto. It could be a hard sell, depending on one's interest in opera or puppets, but it is worth the visit.
You will need to adjust your thinking to take in the tiny stage, which at first looks a bit silly. It has been said that there are no bad seats, as it is a small auditorium. However, the ticket prices are reasonable, and if you can, sit near the front. These are not full-size people after all, so the closer you are, the better.
About 10 minutes into the show, you will forget that you are looking at puppets. (Full stop.) You will find yourself questioning why the actors' lips aren't moving as they sing. You will even be a bit shocked when a puppet moves across the stage in a way a person never could. And you will probably be a bit taken aback at the giant puppeteers (giant!) who appear, via a mirror, at a 45-degree angle onstage at the end of the play to take their bows.
The theater has been around for more than 90 years, and it is on many must-see lists for Salzburg - for good reason. The theater leans heavily on the operas of Mozart (no surprise), but they also perform a limited number of operas by other composers, including Rossini and Strauss.
If you get a chance, let this magical experience take you away. If you love opera, just do it. If you are with someone not yet enamored of the art form, this is an interesting way of introducing them to opera’s delights.