Originally Posted by Mizunara

Those won't do anything for you at Narita. There's an observation deck to look out over the apron and get some obstructed views to one of the runways, but apart from that and a handful of restaurants and shops, no butterfly gardens or indoor waterfalls if you're comparing it to Changi.

Other than just killing time at the airport, you may find more things to do back walking around Narita city proper. It's just a few minutes on the train from the airport.