In 2008, when that was written, SDL required a graphics card - hence the readme saying a graphics card is required.
The whole point of this thread is that SDL has been ported to AGA, so programs which used to require a graphics card can now be run on AGA (presumably as long as the colour depth is ok - which Exult should be as it ran on VGA).
If Exult doesn't run then it must be doing something which AGA can't handle, or there's a bug in SDL AGA (more likely, given it's still under development - and I don't think there's anything demanding likely in Exult)
Either way, it's a perfectly valid program to try - I think SDL AGA should be able to handle it eventually (given the very good work I believe has been done so far!)
