I feel like compared to some of the other Osamu Tezuka shorts I've seen, The Drop is a bit disappointing. It doesn't really feel coherent in the way his better films do.
And the idea of "coherency" is used in a relative way here, given his stuff's usually chaotic. But he's usually better at making chaotic little short films that play by a quirky and distinct set of rules, or exist within a ridiculous yet consistent world. The Drop disappoints a little in that regard, and one part of the animation bugged me (the sky and water seeming to flip at certain points, maybe intentionally?).
But it is also pretty funny, at least, and the premise is sound. It's funny to see a guy battle to get a drop of water in his mouth, and the ending is entertaining. Just fell a little flat overall, though.
