the only thing I think is glaring is how bright the lead can be at parts. The FM on that heis is giving it a LOT of high end information that might be good to either completely filter out (like 8k and above) or to filter out over time with a filter envelope!
If I'm wrong and that's actually a space synth, the the same thing can be pulled off with the mod envelope.
Or just slap an auto filter on it... a lot of different approaches, see which one works for it.