I understand that the number of pages of this comic - and not knowing what's it about - might intimidate you.
So here's a suggestion, if you don't want to read the original 5 volumes of the story, and want to get acquainted with the story type and some of characters first.
Pull down the windows and search the stories suggested by Nicoli.
You can start from multiple sides and then jump right back in :D
The Balthasar universe is disposed on an infinite canvas that is constantly expanding, and this requires very often for a certain level of focus, and sometimes for a re-read (actually if you re-read it anyways, just for the heck of it, you would discover that I planted stuff along the way, hidden in plain sight and you'd get a kick out of it).
My targeted audience is 25 years and above, because it takes a lot of "suspension of disbelief" to go through the first chapters - as the first impression may be that this is just another silly this and that and it makes no sense, whereby it is merely setting up to spoof genres and tropes in a very Monty Python style.
So the targeted audience is high because it requires a certain maturity, knowledge of some of the old tropes and lots and lots of patience. :D