There are many and Crybaby adds some more like empathy which was was present, but not emphasized in the manga, but the manga alone is a strong condemnation of social darwinism and war.
At the risk of sounding like some SJW liberal, it also strongly condemns xenophobia. Crybaby downplayed that aspect a lot, but Nagai delivers that with a hatchet in his manga. It also dwells a bit into the human psyche which is really interesting to me.
Just read this thread for example>>174275427
This is a pre-Devilman story done by Nagai that was reused in Devilman. You don't even need to know Japanese to know what's going on.