Definitely not bad, but things got to be rather confusing after a while, especially once you got to about 18 or so categories and started to forget which was which. And, additionally, some of the combinations made absolutely no sense (like Corpse + Electricity = Death Metal) or weren't quite as expected (I did not expect to need the Alcoholic to make a Pirate). And, although I understand that this was likely done out of programming limitations, I was a little disappointed that some combinations didn't work until you entered the third part (like Rocket + Man = Astronaut) or were changed afterwards (like Assassin + Warrior = Corpse + Blood + Assassin before but didn't make anything after). And, unfortunately, the hints didn't really help with some of these.
Though, admittedly, I can forgive some of the above because of some of the interesting combinations and changes (such as Snake + Airplane = Censored or Apple + Cellphone going from Gold x3 before the third part to Religion afterwards).
Overall, pretty good, but this might be getting to the limits of playability as it is, given the complexity and the sometimes apocryphal combinations.