pretty good
i liked it, and i played it right through to the end (although i told myself 'after this level, im going to stop playing' and it turned out that was the last level anyway)
my main problem was the difficultly level, far to easy. you need to make the enemys move and shoot faster and do more damage. all enemys were easy to manuver around and were nothing but a slight anoyance in the background. and the healing system was FAR to effective. lastly, i found the movement of your saucer just a bit to sensitive.
its a good idea, but should be improved upon. like insted of allowing the player to transfere thier constantly regenerating energy into health, prehaps you could make enemys drop health packs insted? this would also give a point to actually killing the enemys, as i found myself ignoring them and just flying around them. also a boss or two would of made a nice challenge. prehaps a giant cannon, or a high-tech helicopter? that would also add a bit of needed variation to the game since the idea is the same on every level, just with different building skins and background, and eventually enemys.
over all, i found this game felt more like a work in progress and i would really recommend revisting this game and improving some of the factors i forementioned. this has the potential to be a great game.
good luck in your future games and animations.
Jordan Sparkes.