first one is too busy, i think; too much sameness, thin it out some. and letters i think could have been done differently, more like in the third one or maybe more towards graffiti font.
the second one look good for a starter, but i think it needs to explore more the crossfire theme(maybe with the cross hairs?) and more emphasis on red or more red and less yellow.
third one, again, something different with the letters, but i like how they have the neon sign glow thing.
last one, too much red, maybe add some black lines in the fist or the letters and the "Nosebleed" is not as easy to make our as "Records".
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overall, as Orphanix said, needs to be more color smart(like, complimenting colors, like, blue and red, black and white, orange and green(i think)... and so on, i just don't know all the examples of how they). just keep at it, it will get better. the important thing is, you are trying, and that i applaud