I slightly wish I hadn't. A substantial whack of the humour relies on pretty offensive stereotypes - sub-Saharan Africans depicted as leopard-skin wearing savages. (Cleopatra, noticeably darker-skinned than Caesar, does make an appearance as the only significant female character, but is nothing like the memorable co-protagonist of one of the earlier books.) Sure, the Europeans are targeted too - the Spanish and Portuguese feuding over incomprehensible differences, the Brits being posh etc. But there's too much punching down.
The major theme of the book is an apparent choice between reversion to childhood, or being transformed into stone - both of these happen to the unfortunate Obelix before he is restored to his usual self; the chief baddy becomes a statue and the nice rebel slaves are returned to eternal boyhood on the island of Atlantis. I must say that I might have been better to rely on my youthful memories of Asterix rather than return to him now.