for grade a (without .) you must never get hit. for level 1 its definitly doable, if you got all upgradepoints its really easy (basic weapon everything, dont take the health/shield/energy upgrades till the boss, then take first shield, move your ship directly over boss, second shield, too -> boss down)
didnt test this tactic for other levels...
It´s not just a game. It´s a piece of art.
/sign
As a game it's a lot too easy, but it was still really pleasing to play. Good music, good graphics.
Would have been boring if it would have been longer. Then you would have to change the gameplay somehow.