Jacky Cheung did not receive an Oscar nomination for portraying Fly in As Tears Go By.
Now I write that it is like his Mean Streets, in part because you can see the beginnings of him fashioning his personal unique style, but also the stories are very similair. Both films focus on small time street toughs. In both films we have the lead as the more stable of the two, here Wah played by Andy Lau, who while dealing with underworld tries to find romance while also dealing with his hotheaded friend, in this film younger brother, played here by Jacky Cheung. As with Robert De Niro's Jacky Boy from that film, Fly is a wildcard hotshot with a desire to make name without having any sense. Now I'll admit making this direct comparison won't do Cheung any great favors against prime form De Niro. Cheung to his own credit though finds his own way with the role of Fly from his first scene where he struggles to procure a debt from another denizen of the underworld. Cheung brings the right overt bluster to the role, as in these confrontational moments everything is heightened in his body language and every delivery. Cheung's approach though fits this wholly in creating he sense of the miserable effort Fly puts in trying to be more than he is. Cheung properly doesn't make it look easy rather showing Fly's attempt to be tough while never evoking that needed confidence to truly be dangerous, setting up so well Fly's reliance on Wah to actually ever get anything done.
Throughout he film Fly essentially acts as Wah's anchor towards the bad things in life as he continues to fumble his way as a wannabe gangster, usually leaving Wah to get involved to save him. Cheung is effective in all of his scene in realizing the particularly pathetic state of the man whether he is putting on such a ridiculous act of trying to be the "man of the streets" or just revealing the nothing of the man that Fly is whenever he is a physical wreck after once again failing to live up to his "name". There is only a brief respite when he placed into a normal job only slightly outside of the underworld as a street vendor, where Cheung is quite good in showing the sheer ambivalence of Fly towards the whole thing, and the severe disdain whenever he is called upon his position. Cheung finds that right type of uncontrolled spark in his performance that makes every foolish action and overreaction of Fly natural to his constant state of inadequacy to be more than he is, yet always having that intense need to be so. Now importantly Cheung creates the right underlying connection in his scenes with Lau to suggest their history in their interactions to give an understanding to Wah's continued support of him. As is proper thug Cheung essentially makes Fly this ticking time bomb of emotion that eventually leads to an real outburst of true violence by the end. This is the natural progression as realized by Cheung's performance and there is a definite power to the final minutes of the film where the wannabe tries to be the real gangster. This performance doesn't quite reach the heights of say a De Niro in Mean Streets, however it still stands as a strong portrayal of the wannabe set on a terrible crash course.