The Elder Scrolls IV: Oblivion
The 1.0 version of The Elder Scrolls IV: Oblivion for Mac is available as a free download on our website.
From the developer:
Oblivion is a single-player game that takes place in Tamriel's capital province, Cyrodiil. You are given the task of finding the hidden heir to a throne that sits empty, the previous emperor having been killed by an unknown assassin. With no true Emperor, the gates to Oblivion (the equivalent of hell in the world of Tamriel) open, and demons begin to invade Cyrodiil and attack its people and towns.
You may want to check out more software for Mac, such as Volume-Scroll, Elder Sign: Omens or Ultima IV: Quest of the Avatar, which might be similar to The Elder Scrolls IV: Oblivion.