There's also this new inflatable park in Bradford city centre. funzy.co.uk/. There's also a Hollywood bowl and laser zone on the outskirts.
Would definitely recommend the ice cream farm at Tong, Goodalls, they're amazing.
Brimham rocks is good for a free day out, loads of picnic space and masses of rocks to climb on.
Ilkley - for the moors, and Betty's tea room.
Leeds city centre - good for shopping, cinema, nice restaurants, couple of escape rooms, indoor crazy golf
Temple newsman - lovely cafe, good for walks, go ape
If they're into skating/ scooting/ biking there's a skate park called the works and an urban bike park as well in Leeds.
Coast - about 90 mins from the west coast so quicker than the east, Southport is meant to be lovely but Blackpool maybe more appealing for the pleasure beach, sandcastle swimming centre, loads of amusements