Eeh-yah. Finally, after some days of trying hard, I managed to beat this baddie. It was tough, believe me!
The game shown here is called Eternal Daughter and it's made by Blackeye Software (The team doesn't exist anymore, but if you want to try this, google with Derek Yu). I recommend that all you who watch this video play the game, it's worth it.
Oh, and for some strange lags and pauses in the game, the game uses MIDI's, and when the track starts again, the game lags a bit.