Luke seems to have a different favorite toy each week. Last week it was his train set.
He only likes the straight pieces. I think they're easier for him to link together. The thing is that in the Ikea set, there aren't very many straight ones. Luke doesn't seem to mind. He sets them up with the tunnel at the end. He puts the train at the top of the tunnel and says, "On mark, get set, Goooooo!" and then watches it run down the track and fall off onto the floor.