Well mine's still young but biking was always a part of what we do...trailer, followed by trail a bike, then riding solo, to a 20" mtb.
Part of what I always did was make the bike a means to get to something they were interested in. A saturday morn ride with just the 2 of us to get pastries at the neighborhood coffee shop. A ride to feed the ducks at the neighborhood pond. Sometimes we do a long paved trail along a small river...the destination is a couple of nice playgrounds and some low water crossing where we stop to play. Eventually it lead to mine and one of the neighbor kids just liking to play on our street, but first they have to associate a bike w/fun, not something they're forced to do. And I'd never pit an outdoor activity against the video game.
For the OP, you have to figure out what your kid would like outside the house and integrate that into a bike ride. Like others said, a ride to see a bunch of trees & rocks may not float his boat. A ride to a local ice cream shop, or even to a video game store perhaps. There's got to be something in it for him. Maybe, eventually, you'll get him out on the trails, but I think you have to associate biking with fun and then try to move to biking to enjoy the outdoors.