Much has been made over the years about the inferiority of 'I've Got Batman In My Basement' (word has it even co-creator Bruce Timm has denounced it). There's substance to this, and it's due to both script and execution.
"Batman: The Animated Series" was aimed at children, so telling this story from the kids' perspective isn't a crime. But the characters aren't very bright, especially when they serve as detectives. There's a silly tone to this that's uncharacteristic of the show's darker intent, and it even goes "Home Alone" when the main character, Sherman defends his apartment from The Penguin's thugs. Where's Batman in all of this? Out cold after being gassed by Cobblepot. It's a cheap stunt. Add in some low-quality animation (rife with errors) and it does seem like a half-hearted effort.
There's nothing here that really irked me, but I agree that it feels like something slapped together at a late hour. Worst ever? Can't tell; I don't remember many bad episodes on this show. Then again, they'd already set the bar so high that that's still better than most of its contemporaries.
5/10