The humor isn't for everyone, the best way I can describe it is surreal. Most attempts at a laugh are usually made as wordplay mixed with puns delivered as quickly as possible, which may or may not sometimes be lost in translation. Each episode is around a minute and a half, so there's little harm in giving a couple a shot to see if you'd enjoy it.
The 3D visuals live up to the title and are quite charming, I honestly prefer the dated look compared to the newer 2017~2020 seasons.
On the surface, there is no plot. We get tidbits of lore via random statements but they are rarely elaborated on and when they are it's usually for a joke. It's similar to a series like ENA, where it seems to be illogical nonsense that gives you nothing but questions but as the series progresses you're given enough information to sort out events and form a timeline. Without getting into spoilers, this is actually to the series' benefit and the show does something pretty cool with it later on. I might be hyping it up too much as I went into this series with no expectations, so by the end of the franchise I was pleasantly surprised.
I'm unsure if I'd call this series a hidden gem but I think it's worth a watch. I highly recommend watching the seasons in this order:
Fireball Charming > Fireball > Fireball Humorous > Gebäude Bäude
