I really like the concept, and the art is INCREDIBLE!
However, I will say that while the concept is good, the game doesn't really seem to use it very well; if the game didn't had the mechanic of less fuel = more speed it would still largely be the same. In fact, in some levels - for example, level 6 - I was going so fast that I was ramming into obstacles that were off-sceen seconds before, giving no time to react.
Outside of that, I really like the game; the visual and sounds are great, and I really appreciate all the available settings the game gives.