Thanks for the comments! 
Changed the first level a bit so it should be easier now.
@Hansdampf
Not sure if this was clear. The scoring can differ alot between enemies depending on how high your multiplier is (right above the ship). For every enemy you destroy (and bonuses) the multiplier is increased by one (and it is set to zero if you get hit or if you don’t increase the multiplier within a few seconds). The “base points” for an enemy is then multiplied with the multiplier (for example 150 * 10, if multiplier is 10). Good idea with the bullets on 2nd boss btw. There are only 3 types of weapons in the game so far (super bomb on SPACE).
Yeah the 2nd boss might be hard, but a reason for that is because the game only has 2 levels so far. When I make a 3rd level I will probably make the 2nd boss a bit easier.