I also couldn't get past the character select screen. So, I can only offer these tips for selecting characters, cribbed directly from the manual:
Looking at the screen you will see twelve portraits. The top line are all warriors. The three in the bottom left are all Clerics and the rest Mages.
To choose your hero first click on the window underneath the character class you wish to pick (the button will "depress") and then click on the portrait of the hero you require.
To move on, you are supposed to click the small button in the lower right. When I tried, it fades to black and nothing seems to happen...
If you manage to get past the intro, though, you can reference the manual for the game here:
http://www.lemonamiga.com/games/docs_print.php?id=17