While I do like the designs of Limey and Tanana, they don't really have discernible faces. I understand that they're based on slugs, and that what faces they do have are at the top of the sprite, but it's hard to parse them as Pokemon. I happen to be of the opinion that not all Pokemon need to have recognizable cartoonie faces, but there's not much of a precedent for that, so Limey ends up looking like nothing more than an odd banana. Then again, judging from Gorm's description that may be what you're going for. For the record, I do like the expressions on the "faces" of both sprites; unless I'm misinterpreting things, they look cute and incredibly happy.
Buzzly and Grizzect are a bit more complex. With the Buzzly sprite, it feels a little too busy, mainly because of how much its parts overlap. One of its arms is overlapping a wing, which is overlapping the body, and one pixel below that is the leg, also overlapping the body. You have to take a closer look to really see what's what, and worst of all, the cool spiral design on its abdomen is easy to miss entirely. If you look at Beedrill's sprites, which have a very similar body structure, you'll see that after the first generation the artists have opted to draw it in poses with minimal overlap. In fact, where the arms and legs connect to the thorax was changed from the front to the sides to facilitate this. I think changes as simple as setting Buzzly's wings a bit higher and changing the positions of (or removing) the arms would do wonders for its visual clarity.
As for Grizzect, I originally thought that the arms overlapping the body was bothering me, but after thinking on it I've realized that's not the issue (though one of the arms could be in a different position, just sayin'). What seems off about Grizzect is the contrast on the torso. The colors, contrast, shading, and patterns on the other three sprites are fantastic, but this one doesn't feel quite right. Maybe it's the fact that black lines are used in the wings but not the center of the body, maybe it's the lack of shading on the brown parts while the yellow parts are shaded heavily.
All that aside, I really do like your designs and use of color, and hope to see more from you in the future. Maybe a Buzzly showing off its neat spiral design?