"The trick to fight the bosses is to fill up with powerups. If you have a shield upgrade, you won't get 1-shotted. Also, it's wise to let go the throttle when attacking boss to maximize attack time. One last trick – going counter clockwise around the boss, it's easier to avoid the enemy fire. Remember to go fill up on energy when you're hit."

Thanks JP. The more I play this game the better I like it.