These aren't too bad actually...
1. You need to vary the outlining. where the lightest tone touches the outlining, you need to lighten up the outlining there. so the bright spot on ironrhy's head would have more of a grayish toned outlining, instead of black.
2. the shading is also a bit awkward. There seems to be multiple light sources. Again, looking at ironrhy, his head is shaded lighter on the top left, and on the belly... which would indicate that he has a light shining from above, and below. You want to keep your light source consistant, and coming from the top left of the sprite.
3. The anatomy of these are very geometric. the nails are very V shaped, the shading it's self it consistant of strait lines, the grasolo's arm is rigid and strait... try not to use so many long strait lines. Instead, try to make the body's have more natrual curves. Also try to make some parts more difinitive. Irono's back leg is mixed in with the lot of his body, and he has a strange ___ under his body that is filled in with grey.
Like I said, they aren't bad, but they definitely need some work. I rate Ironhy at a six, mostly because his shading and outlining are off, but he also has some anatomy issues in the rear, and the under belly.
Irono is a four. the same issues as ironhry, but also, he is very awkward and unorganized looking. i can tell that his head is looking right, but from there, i cant tell where the rest of his body is pointing... the apendiges are just to small.
Grasolo is a five. He is more distinguishable in the sense that i can see where everything is, but he still has the "rigid" problem, as well as the same problems as ironhy. Try to curve his arm more, and his feet need to be more rounded... not circle like...but just not as rigid.
regimark is a six out of ten. he needs some redoing on the shading, and his outlining is in need of som lightening up, but the other thing is add more green tones. his monotone'd green is doing his metallic body no justice. study the shading of other metal pokemon and then try to apply it to him.
Don't get discouraged, i know it's a LOT to have to work on, but like all great art, spriting takes some time. Keep at it though, and i hope you fix them and post them next to the old ones!
Keep Spriting!