There are some serious scaling issues with the exp. points in the higher ends. A Light-Year is 2 billion, and the North America Nebula is 2.5 billion, despite being almost an order of magnitude larger. It wouldn't be as much of an issue if the levels in that area didn't take so many points to reach.
When you said the "Cargo is extremely heavy" I didn't expect it to be so heavy that the upper stage would actually accelerate downwards at full throttle w/boosters. Guess I need to upgrade. Well done, well done indeed.
Couple of tricks I've found. When needing higher level items, just purchase the magnet, double value, and Power Swing. Use the power swing to fly far and fast just above the ground. and the magnet and double value for lots of coins. When going for the hard badge, use Power Swing, Super Run, and Airboost or Superstop. Use power swing and airboost to go long and super run to get back up there, or if you wen with superstop, use it if you either get bumped backwards, or are about to fly over the hole.
Good Game, but the option to turn off some of the laggier items/decrease the quality. I have an older computer and love these types of games. I however cannot because the custom cursor kills flash player, and everything is of such a high quality that it doesn't help.