This clip goes up to the end of Cinderella Amber (the stage4 boss of the original arcade game) with some competent scoring and survival techniques. There are obviously some points that could be greatly improved upon, such as a better scoring method on Vinogradov (the battleship), and parts of Cinderella Amber.
The key to scoring in Ketsui DS is to use Shot to destroy everything, and only using Lock-On to farm multiplier chips. The reason for this is because your multiplier will drop if you destroy something with Lock-On, whereas it is maintained if you destroy something with Shot. The other key point to scoring is to use all your bombs up - you get bigger chips for bullets closer to you when you bomb, so to maximise chip gain, it is important to play at high-risk.
9