Overall no:
Hovwever:
Combat has been made a bit more complex by the use of 2 defensive value, new shield use and armor piercing value.
magic works quite differnently.
Healing works differnently.
And although not more complexe, classes and racial kit are differnent. For exemple the barbarian is quite different in the Conan RPG then in D&D 3,5 Ed
That would be the main 4 area of difference, which is some aspect makes it more complex.