hon, don't be mad about your sprite repository being ignored; yours was actually made way later and people had made sprites of all the starters before you. this isn't to take your thunder or anything...
now for some quick stuff about your sprite:
ref material:
[spoiler]
some things that immediately jump out at me:
note: when i say left and right, i mean litten's left and right,
- litten's right side of its face in your sprite is too straight. a general rule of thumb is that a border of a pokémon will never appear straight ever; they aren't straight.
- the whiskers are wonky; the one on the right is too large while the one on the left is too small.
- the face being straight gives a blocky appearance to litten's head that is undesired. this also results in a look of deformity; while the eyes of litten make it look like it is facing left as well as everything about its face, the face structure itself looks aligned to face right.
- this is more of a nitpicky problem, but it gets pointed out a lot: your color scheme would go well by itself and if it weren't based off of something, as it has a sense of uniformity. however, your color scheme is actually fairly bright compared to the references (your sprite looks like it has scarlet fur and your black seems to be more influenced by red than the blue it should be. overall, your sprite seems to influenced by red and there needs to be more blue. the actual red parts need to be a more vibrant red.
- the tufts pf fur between the ears are supposed to look more like leaves, per se, and are supposed to come from the upper-forehead. yours are sharp and appear to be coming from the top of the head (yes, there is a difference).
- one thing you'll get hammered a lot for is proportions; litten, being a small cat, should not look as large as, say, rayquaza. the two sprites are compared below and the point is also illustrated in smogon's sprite resource.
[img][img][img]
[img]
excuse me for saying that this makes litten look a giant. you may say that this same effect applies to the seedot i have included in there, to which i respond that it does similarly. however, in-game we see that seedot's sprite is actually adjusted so that it looks like it touches the ground, and only then does it look like it is not a giant. meanwhile, your litten used up all the space given it. the litten shown below is the one currently being used for the repository and we can see that bodily proportions are kept nicely and it just looks better overall.
- your shading gets a bit wonky on the legs, but that is no big deal and easily fixable...
- the dark black outline for the symbol on litten's outline should be replaced with a dark red to make it blend in more.
- overall, dark black outlines shouldn't really be used generously unless if there is little to no sunlight reaching said area.
- your tail isn't pointy enough
- the point at which your litten's tail attaches looks a tad blocky. no biggie, it's easily overlooked.
- your sprite does not look as if it is on even ground (nor does its drawing). this also gives a hard time to a hacker wanting to position it on flat ground in-game when using your sprite...
this is all just me offering little oddities i see on your sprite that i've seen pointed out to other people and to me. and i'm in no way saying that your sprite is bad, but that there are things here and there that detract from the overall beauty if the piece itself. sorry for theoretical discouragement and thanks for reading...