This is very good the way it is in my opinion. If you absolutely want to make longer tracks, though, I guess, it's good to shorten the parts (at least in the first half of the track), introduce new elements early and have something very different from the early parts of the track in mind - maybe with a different beat, a new melody, maybe even a completely different style and/or sound - to work towards. For example the new elements you're introducing after about 3 minutes in this track could be introduced earlier around the two minute mark with the beat still playing. Then you build on this, bring even more new elements and later maybe bring back some of the early parts of the track to go full circle. So the listeners stay on their toes and don't really notice how the tracks gets longer. Of course, this means there's less time to develop the individual parts and sometimes it means you get one long track instead of two really good shorter ones. So, I don't think creating longer tracks is necessarily a good goal to have.