I found this game very funny. Thu humour is good. When you enter the Mafia's club, they all point guns at you, but if you show them the Mafia card you found they put them down and give you a gun, telling you to kill people, you can then arrest them all. Other funny things included are cleaning windows with guns and you butler seems to know you toast was poisoned with salmonella straight away.
Only grammar thing I really noticed was '1' was used once to mean 'one', other than that I didn't see any mistakes.