Yeah could do with better shading they are stuff that haven't been used but not a sprite sheet I just set them like that in paint.net, I thought this was an interesting thing to add and I don't know if you have heard of it but the sprites that are from a side sort of view were going to be for a game like Gain Ground which is a really fun Sega gameI love pixel art! So these are really interesting to me. (I know that some of them are not)
I think you should do some more shading on them, It'd be interesting to see how much better you could get them to look.
These look like sprite sheets, are these for some home-made games?