A when you reach 50 kills (1 kill= 1meteor destroyed) Your bullets will become triple and the GX BOSS will spawn. And at 100 kills the GX BOSS V2 will spawn being 2 times stronger than before. Later at 300 kills the GX BOSS V3 will apear being incredibly strong and almost impossible to defeat.
If you press space key you will activate the shield. Use the arrow keys to move or click the sides.