Adventure Game Studio (AGS) is an open-source tool which is best for creating graphic point and click style adventure games. AGS provides all the tools you need to make a complete game, including graphics, sounds and scripting. It also has a well as a very well documented in program manual and an active and supportive community. It is suitable for an intermediate level, so it would be best to have a little game making experience before you try out this tool.
14th May 2020