There's lots of different ways to play it but some ideas:
(Don't read this unless you are stuck. You may well find your own superior methods and much of the fun is in exploring)
1. When you are in orbit around an attractor try to use the minimum thrust possible to get motes. Use lots of fast motion and take opportunities as they arise. When they do arise don't be afraid to slow it right down to hit your target mote with minimum fuel use. After a while you get a feel for when its best to thrust with or against your motion or perpendicular to it to achieve a rendezvous but experiment with all of these.
2. Make sure you get the most significant motes around an attractor before consuming the attractor since they will tend to scatter once you do.
3. You will need to leave orbit of several attractors to mine the motes around others before you are big enough to consume attractors. When you do the most fuel efficient way to do this would appear to be to thrust with your direction of motion and spiral out (maybe just a quarter/half turn or so depending on where you are in the gravity well) from the current attractor. Sometimes I'll aim to throw myself into a slow orbit right near the boundary going clockwise to rendezvous with the next attractor in which case you need to be ready to slow yourself and dip in a little just as you get there so you are captured in an anti-clockwise orbit around the next attractor. Remember gravity will never be stronger than when you are near the attractor so this is the time to apply thrust to be captured by it. If you are too slow you will shoot out the back and have to use lots of thrust to catch up. Other times I'll thrust out in front of the current attractor and swing into a lower faster anti-clockwise orbit to catch up with the next attractor before thrusting back out to meet it. In all cases when leaving orbit I thrust with my direction of motion (ie perpendicular to the vector joining me with the local attractor) and start thrusting early so that by the time you break orbit you have your desired heading.
4. Try to use the attractor's gravity to get you going generally where you want to go before you consume it. Or at least don't approach it directly from the inside and have it sling you towards the border just before you eat it.
5. There's enough extra mass in this level for you to get big enough to consume the central attractor without consuming all of the others. Once you do the others will hit the boundary and you will complete the level. Though you can also eat all the outer attractors first.
6. All this said, there is room to make mistakes. I've got point 4 completely wrong and eaten stuff in the wrong order (the more you eat the more you waste in thrusting a greater mass around) and still managed to get by.
I guess just generally try to work with gravity and thrust as little as possible. When I talk about thrust above, even when leaving orbit, its generally just a succession of rapid taps, take my bearings, a few more taps to correct etc. Get into a good orbit and then use fast motion to see what you sweep up or what you should go for. And sometimes if you miss your opportunity be prepared to let a mote go until the next close approach. The worst thing you can do is waste a whole heap of fuel chasing something down only to also find that you have also flung yourself out of orbit prematurely.
Ummm, that's about it for the brain dump. I'd be interested to hear what other people do. I've got up to epicycles forever 4 and I still feel like I'm not doing it quite right
