I'm not really qualified to critique design, but I'll try it anyway. Overall I think they look good, and the top left image is my favorite. Here some things that could maybe be improved.
- I think Cyborg Chronicles should be in "Title Case" (since it's a title after all).
- The double left edge of the red C in the top right image doesn't do it for me.
- The very dark red of the C in the top left image is hard to distinguish from the black, maybe lighten it a little or just make it black.
- I think that "Card" in the upper right image is more visually interesting than "CARD" in the others. The font is pretty plain if you only look at uppercase letters, but the lowercase letters have more character.
- The thick left edge of the rightmost card in the bottom image bothers me, I think it might look better being the same width as the other edges.
- Breaking the "SHIFTER" into individual characters and rotating them to slightly different angles might make it more interesting. Something like this:
All in all, I think something like a cross between the top two images, more similar to the image on the left, would be really nice.