These short stories won't convince you that Gosho Aoyama is some kind of master storyteller. They will definitely convince you that he is a seriously weird dude who would be writing seriously weird things if Detective Conan wasn't so popular and profitable. And, so, if you've been watching Detective Conan and want a break, this is a fine option. It's fun, first and foremost. Any Conan fan can check these out. They're not just for completionists. The best thing about it for me was the character designs and general art style were still running on the 90s cel-animated Detective Conan aesthetic. I love the way DetectiveConan looks at the very beginning, and this is a slight bump in quality above that, to make it suitable for a direct-to-VHS OVA special.
Most of the stories are fine-to-good. The first half are definitely the strongest, with the best gimmicks. I was hooked through the time machine one and the Christmas one had an interesting flavor. The interstitials about the Kudo parents from Detective Conan were fun, too. Who could say "no" to a Baby Conan story? The second half were not so good, especially as they leaned harder into not-quite ecchi territory that Aoyama is apparently not equipped to tread in. The kendo one was a snoozer that I watched at 2x speed. None of them are bad wastes of time, but some are stronger than others.