I got the game yesterday (well I had it in 2009 but traded it in then cheated gamerscore so I've actually got 70G unattainable right now but it shows on my screen) and I got 490G + 70G from before. I completed the game within 18 hours lol.
I enjoyed it. Scarlet did do my head in first time round, 'cos I couldn't master dodging her ceiling attack but I figured out how. When you hear her scream, she's on the ceiling. walk forward and only press B once when it pops up. I did this second try and beat her. 'Cos on my first try I just kept panicking and pressed B like a madman.
It's not a frustrating game by any means, you just have to understand it. And yeah, needlers and schisms did my head in too with dodging... Smog's did my head in 'cos I barely ever had any ammo.