It works fine, as long as you pick 'windowed' in the Overlord settings. Played it from start to finish.
The ground looks washed out, there are some graphics glitches and objects seem to disappear after they get further away than some fixed distance. But this last one might be due to it running windowed.
An advantage to running windowed: you can keep your system clock visible so you don't end up playing all night ;)