I never meant to review anything here on MAL, but here I go.
The recommendation below labels this OVA "horrible". What I'll try to say is: it's NOT.
It may be old. It may be odd. But it's not that terribly bad.
NOTE: I haven't read the manga.
Well, you've read the plot synopsis haven't you. That's the story. It's just a single-episoded OVA, and that makes the plot [just a little] bit rushed. What you get is: the beginning - something episodic in the middle - and then, the end, which turns out to be quite open (well, the manga used to be on-going back then).
What's really good is comedy; it varies from being naive and all-too-simple to being surprisingly refreshing and enjoyable (no really!).
My God yes, it's oldschool. And it's none of a masterpiece. If you hate 80s anime artwork and find it out-of-date, better skip. If you like it, you may even find it quite pleasing at times.
Nothing outstanding as well. Sometimes you just don't notice the music; though it gets better in the final part of the OVA. The opening and the ending sequences are nice (op: cute; en: nostalgic). The sound effects are quite good for a 80s anime. Seiyuus do a decent job.
If you're still here and have read the above, you may ask "why on Earth shall I watch it?". Well, here's the possible answer.
The characters ARE great. It would be ridiculous to expect any character developement; still, they're bright and catchy. A fluffy, pink, mouselike creature that seems to be the head of the gang. The omnivore mecha robot with an extremely reserved personality. A brain-like something that's complaining all the time. A furry-like female who has special powers and rides a motorcycle-like vehicle. An aged alien lady who appears to be a loli-lover. The Cherry Hill dragonflies who just look like dragonflies. And a pack of other characters, each of them unique in their own way. Even if this was the worst anime of all time, these guys'd drag it out of hell.
That depends. It's too subjective. I DID enjoy this.
If you want to have a good laugh; if you want to see something a bit different; if you don't get sick every time you see the 80s artstyle, give it a try.
I hope this helped somehow in explaining why on Anika shall you spend 45 minutes and watch it. Why on... Anika? Go find out.