Gurvak: It appears to be only a Demo Version, after a exact mission the campaign end in the title screen,
If I win this exact mission the campaign instantly quits and don't let me play any further.
Am i missing something?
It is a well known bug in the current version of the game. The game developers show no interest in fixing it, saying they've moved onto other games and don't plan to do any more work on Omerta, and GoG doesn't seem to care. Basically, the developers and GoG are knowingly ripping people off.
The official statement from Kalypso, the developer of the game, when asked about a patch to fix the problem is this:
"Tropico 5 was released just a little over a month ago, Omerta is now one and a half year old. Unfortunately we can't provide patch support on all games years after release, the team is simply not big enough to accomodate for this. Active development on the Omerta project has stopped and moved to Tropico 5."
It looks like, at least according to Kalypso, we will never see a fix to this issue.