OK, so it's perhaps the definitive fish-out-of-water story (Ho, Ho!) but what really makes this work hasn't a whole lot to do with the properties of marine life. Sans fin, essentially what we've got here is too shy people whose cultural differences make it hard for them to find love together. When you break it down like that, it isn't so unusual after all, and it's actually mighty touching. Who but a complete cynic wouldn't love a charming fable that tells us we can sometimes get what we're searching for, in the end?! It may be a funny line, but we should also be able to identify with Allen's pain when he tries to come to terms with the fact that his love match is a... fish.
It's this smattering of pathos which takes a funny scenario and elevates it toward becoming a classic relationship movie. Anyone who's ever been confused about what they want from life should gain a few knowing laughs from this as it floats pleasantly along. So what are you waiting for? Hop right in, the water is fine!