I'm... not super sure what you've done with these, aside from some recoloring.
More over, why were these posted in the Main tSR fourm rather than the Custom Sprites fourm? Shouldn't this be moved?
As far as the sprites go, I guess they're okay, although the color choices for the text boxes in the 8-bit CD sprite sheet is a bit odd.
My apologies. I am new here. The 8-bit Sonic sprites took a long while to make actually. I tried to get them as close to Sonic CD's sprites as much as possible. My hack in progress for Master System uses them, but more poses have been added since then. Same for the 32-bit-ish Sonic sprites. The CD HUD/map/items sheet was done for a friend.
Got some good stuff here. The 8bit Sonic CD ones are pretty neat, (truthfully I think they look better than all of SEGA's official Game Gear / Master Styem sprites, good job!). For the Sonic Crackers / Sonic 4ish sprites I recommend using more colors if you are really going for a next gen look. Without zooming really close in its hard to tell any work has been done at all, even though I do see the extra shading. Keep up the good work!