First of all, good luck with that hack of yours. In addition to what others said, I would advise you not to cover your background with black (the 0/0/0 is still different than the the 12 RGB one used in the pokemon games, but we still can't spot the difference with the naked eye), because the black outlines are covered by that background.
I'm also curious as to why nobody hasn't pointed that out yet...
It almost seems like you're getting those sprites right from pe2k without changing the background, which used to be transparent.
So, let's give it a shot:
Anoleaf~
Pretty good concept+shading. The bad thing is on the body structure, though.
You made it look like it's going to charge, as its front feet are higher than the back ones. Well, ubless this was your purpose, then you should make them lower, or raise the back ones (though that would make the sprite smaller).
Also, what's with the left back leg? the belly that actually distinguishes it as the 'left back leg' is gone, and it gives the impression of having 3 feet on the right side...
Finally, you can raise the tail by a pixel, or two, so that it won't have to collide with the head leaves.
Now, the outlines are the same everywhere. You should darken them on the points where there is no apparent light source.
Leafrill~
The comments are almost identical to the previous sprite. The front left leg should be shown less, because it seems like it's longer than the right one - because the body can't fold that much so that both front legs would be of the same size.
The tail can be moved a little as well, as here it collides with the left back leg.
Outlines, same as above. Plus, there is no outline variation on the leaves.
Chlorofile~
This is one great concept. It's like the jungle imprinted on a pokemon.
The leaves are well-drawn, and there seems to be almost no proportion error here.
(you can fix the back leg a bit though, to make it look less stiff)
The outlines, though, remain the same. A lot of work and darker outlines on some spots.
You can lower the shading on the right front leg, as there is the head leaf right in front of it.
P.S: is that Feraligatr's jaw or am I seeing things?
Emberd~
Unlike the previous sprites, this one looks like it was lazy-drawn. You definately need to put some more work into it.
Its tail is weirdly placed; could be higher. The hands are on a different height scale as well. the fire that is overlapped by the left leg makes the whole area look blurry.
Finally, it looks more like a monkey, than a bird to me. Mostly due to the beak, chest and legs, oh, and the pose.
I understand that some of the palette and outline issues can't be fixed, because you are using the default starters' colour palette, but you can always experiment. Use a new palette!
Cindrun~
Now that's a change. Definately cooler, looks like a raptor bird, with a lot of stuff to keep you busy looking at it. Still...
The chest pops out like a yellow baloon, is it supposed to look like that?
Hmm, the tail, though pose-scratched, reminds me of Milotic's.
The left leg could be raised a bit. And...the back of the neck twist suddenly, therefore doesn't connect properly with the body.
The outline issues remain.
Burstrech~
Although this looks amazing, concept-wise, it's not really different from the previous sprite. It almost looks like it didn't evolve at all, just grew angrier.
So, it's probably the same in terms of outlining as the previous one. The neck, again, twists suddenly.
Charizard's palette, eh...oh boy. You can do better than that!
Oh, and I almost forgot, its tail seems fatter than it should be.
Generally, your outlining needs work. You can take a look at other people's work or just at normal pokemon sprites, and get familiar as to how it goes. Since you're drawing 3rd gen style.
Take care, I hope we can see more of your work soon. See you around!
