The Niseko Park Hotel is a good example of an older fashioned Japanese ski resort hotel. The building is a bit old, and rabbit warren-like, as many of these hotels were, but it seemed to be in acceptable condition. Our room was quite small, but clean, with a small unit bath/toilet room, basin, a hot water pot and a small safe and fridge.
The hotel onsen and rotenburo were clean and maintained, and there was also a small sauna which was unexpected.
Breakfast was rather generic - runny scrambled eggs, boiled sausages, bread, rice, basic salad etc., which again is fairly normal for this era of hotel - but fine for a few mornings.
Board/ski and drying rooms were decent, and the hotel is about 200m away from the main ticketing area for Hirafu which is quite convenient.
We were there during the Japanese Setsubun festival (clearing out bad spirits) and the hotel did a fairly basic example of it which pleased the kids, so points for thinking to incorporate that.
As for guests, very international, and whilst one member of staff spoke English, they made good usage of translation software at the front desk for those who didn't speak Japanese, or the English speaker was off duty.
One minor note (depending on your requirements): when we were there the in-room wifi wasn't functioning for 3 of the 4 days, though the common area's was. (The staff didn't seem too happy to deal with that either, and kept saying to just keep trying).