Orc campaign kinda just...stops?

[Xidus]

That is the last orc mission. I don't remember if there is supposed to be more fmv or not.

From what I've seen hard mode has less gold reward at the end of the mission. The manual says there are more enemies and they are of higher level. I'm not sure of other differences. Probably shorter turn limit too.

[GeneralGonzo]

If you already completed the human campaign before the orc one, you now have access to the third one, the elven campaign, which ends the story then....

The difficult setting don´t change the turns you need for gold, silver and bronze, instead it changes the number of enemies you will encounter.
Let me say that between easy and hard, there is a big difference.....