Ok, a few comments:
Goomba~
The colors are very dull and need more AA'ing. The legs should be shaped more like Kirby's. Use pallette from official sprites please.
Koopa~
I does it have a standing up pose? On four legs, the legs seem too close together and the right eye looks a little wierd. The shell also needs a redo. For the red use official pallette.
PPlant~
Use official pallette, the white is a bit sucky and the red is ok. ANd you might want to make the leaves flat unless they go into the tiles or your going to make a stem...
BowserJr~
Good but head looks a bit big for some reason.
Yoshi~
Please show other hand. Again I really don't like the white, so use official pallette colors for it. Head also looks wierd for some reason...
Wiggler~
The new one is great but I mess around with the flower because it looks squished...
~ I really don't know if I am looking at the correct and most updated ones but I think I am... Anyways these are IMO and I really don't know if I am correct...
EDIT: If you will allow Kirby64 enemies, I do have some...
Goomba~
The colors are very dull and need more AA'ing. The legs should be shaped more like Kirby's. Use pallette from official sprites please.
Koopa~
I does it have a standing up pose? On four legs, the legs seem too close together and the right eye looks a little wierd. The shell also needs a redo. For the red use official pallette.
PPlant~
Use official pallette, the white is a bit sucky and the red is ok. ANd you might want to make the leaves flat unless they go into the tiles or your going to make a stem...
BowserJr~
Good but head looks a bit big for some reason.
Yoshi~
Please show other hand. Again I really don't like the white, so use official pallette colors for it. Head also looks wierd for some reason...
Wiggler~
The new one is great but I mess around with the flower because it looks squished...
~ I really don't know if I am looking at the correct and most updated ones but I think I am... Anyways these are IMO and I really don't know if I am correct...
EDIT: If you will allow Kirby64 enemies, I do have some...