I liked it
I have never really seen a game like this before, but I liked it. It was nice and simple. It did required some thinking sometimes and it was quite challenging, cause the game starts to get harder pretty soon. The graphics were pretty good too, and I liked the music that was playing at the background.
There were not many bad parts in this game. Only one thing: When the fuel bar is full, the level ends immediatly while I was still halfway in a big combo. This annoyed me a little, since I could´ve had a lot more points in the end. Please just let the game finish it´s combo before you go to the next level. As for improvements: It would be nice if there were more special items in it. The only thing I saw were a few bombs that came in every once in a while and they were not that usefull.
Overall 8 out of 10, 4 out of 5. It was a good game, although I couldn´t get any further then level 6 =) Anyway, I hope you´ll make some more of these, keep up the good work.