Every advert for it I have seen/read calls it a "family friendly" coaster, or in official HK website a family friendly carnival coaster. I don't know many carnival rides, or family friendly coasters that are all that long or full of large drops/thrills.
The ride itself seems to be a perfect delivery on 1) great frozen themeing; 2) accessible to almost all ages with a very low height requirement; 3) gets up to some speed/trill, but nothing to extreme. To give a subjective example I was forced/blackmailed/guiltripped into riding 7DMT my last trip at MK. I don't like roller coasters/thrill rides, but had to do it, and found it to be basically at my limit of comfort. I did it, made it through and was ok, but i wouldn't want to ride anything "bigger" HK Frozen gives you some of the speed similar to 7DMT, but i thought the drops on 7D were a bit bigger (full admission I haven't checked actual drops on ride, just subjective veiewpoint/feel.) This is the perfect ride for young kids to get into coaster. Great theming, good speed but not going to shake anyone up too badly, and even if your not enjoying it, its not going on so long as to really effect you. Flight of Pandora it is not, but for young kids, to me it beats the hell out of barnstormer or flight of the hippogriff.