It was different from the usual Batman portrayal in that this Batman was not dark at all.
No, this wasn't the dark, brooding Batman, this was the science fictiony, fun Batman that was around in the 1950s and early 1960s.
Now a LOT of Dark Knight fans hated this version at first because...well because they were "Dark Knight" fans.
But a lot of them warmed up to the series over time.
Mainly because it was fun.
I mean this was not a cartoon to be taken seriously.
I dont think you would have seen a lot of musical numbers (or an entire musical episode) in Batman: The Animated Series.
Now that's not to say there were never any serious episodes.
They did the the murder of Bruce Wayne's parents, the death of the Ted Kord Blue Beetle, the creation of Deadman, the death of the JSA's Black Canary, the origin of Gentleman Ghost, and B'wana Beast and the Doom Patrol both being killed in the line of duty.
The last two were especially haunting considering this was supposed to be a "kids" cartoon.