It can be a bit silly but I can't start a game, I don't know how to create a party :p
This is what the manual says:
To add a character to your party, hold down CONTROL and press the KEY LETTER next to the character's name on the list of available characters. A @ will appear next to the character's name, marking him/her as a member of your party.
The game simply ignores me when I press control+letter, no @ appears, nothing happens. What am I doing wrong?

You could try the suggestion in the 3rd post of this thread

Wops, I searched but didn't found that thread.
I can play now, thanks!