Love this game.
I love the sound and ambient music, as well as the graphics. Of course the big laser goes PEWPEWPEW. Only sound that's missing is when your ship becomes damaged.
Levels 58 and 60 were the hardest. I beat level 58 with Lightining, Big Laser, and ShortShield. You had to circle around the middle, spamming lightning, and taking out enemy spawns with the big laser and short shield. Circular motion is key so you don't get rammed. Spam lightning, spam shield, and target spawns with the big laser.
The last boss was the hardest. I used the duck, laser lock, and energy seekers. Use the duck and laserlock as soon as they recharge, and spam missiles in the meantime, and dodge like you've never dodged before!