Anicca is basically like nothing that lasts on this earth can ever be free. There are 5 stages that no human can control: Growing old, Getting ill, death, perishable items perishing ,And the passing of things . And then escaping from these stages is found in the state of nirvana.
Impermanence in Hinduism differs from Anicca in Buddhism because them Hindus think that if you connect with the permanence within yourself you can overcome the impermanence of this world, or something to that extent.
Hindu atman is the truth that exists for everybody. Once you realize atman you become Brahman. Buddha did not accept permanence because all things in this world are in a constant state of change. In Buddhism you cannot overcome impermanence in this world because nothing is permanent; you can only escape it.
Anatman is the denial of a permanent soul. Basically, as we're "reincarnated" we go through renewed cycles of birth, life, old age, and then death. Our senses are stimulated and we have a longing for existance so we are reborn again and again but it's never as a permanent soul.
So the difference of Anicca and Anatman is that Anicca is that nothing in this world can ever be free. Nothing last forever, everything is changing. Even you are not the same person for two moments. You're always different.
Anatman is the changing of the soul. It isn't the same going from life to life, it's not permanent.
Karma is just when you are the next being good deeds are rewarded and evil deeds are punished so that no unwarranted suffering exists and no undeserved pleasure exists. Karma is based of off natural law: a universal justice applicable to everybody. It determines your species, your body, your class, your health, length of your life etc etc etc. Karma can control your rebirth from being a cockroach to a god.
I'm not too familiar with Hinduism but I know in Buddhism gods do not have any kind of supreme power. Gods are like all other creatures; we're all stuck in the same predicament it's just that gods enjoy great amounts of pleasure in heaven so in their past life they had good deeds. The best incarante is human form cuz the gods are so self indulged they can never become enlightened. They're desinted to die and come back at a lesser stage while only a human can obtain enlightenment. As far as Hinduism goes with that.. I'm not too sure.
Anyway, hope that helps clear a lil sumthing up.. if you have more questions you can PM me but I don't know a whole lot cuz I'm not a practicing Buddhist or anything. You can prolly find sum books that go more in depth on it. Payce
Also, Buddhism differs slightly region to region. Vietnamese and Chinese are pretty similar I think. Japanese is different, Korean is kinda different and Tibet is hella different. So interpretations of the divine truths and the eightfold paths also differ from region to region sect to sect etc etc etc. So what I posted is just a pretty general view of it.