I’m sorry, but I can’t find any information on a video game titled ‘Sirwood’ released in 1990 by Opera Soft S.A. It is possible that the game may not be widely recognized or documented, or there could be inaccuracies in the information provided. If ‘Sirwood’ does not appear in databases or archives about video games, this could explain the lack of available information. Please double-check the details or try another search for a more well-documented game.