I think the Schloss Hellbrunn trick fountains have just opened. They’re a lot of fun, but you will get wet so best to go on a warm day. It’s a short bus ride away from Salzburg centre. The Salzburg Zoo is next door too.
There’s a science museum and a natural history museum in the city centre. Neither are great, but they might keep the kids entertained for an hour.
Depending on how old the teens are and whether they can explore on their own, they might like to get the cable car up the Untersberg mountain, and then you can climb the 20 minutes or so to the peak. It’s about a half-hour bus ride away though.
Hangar-77 has lots of racing cars and planes on display. I’ve never been myself so not sure how interactive it is, but might be worth looking into it.
Maybe the salt mines too. Again, I’ve never been but they’re billed as a family attraction and the Hallein one is next to a Celtic village, with entry included with the ticket price.
I’m not sure if any of that is useful for you. I visit either alone or with my partner so I’m not really looking out for family-friendly attractions, but Salzburg is my specialist subject 