Really create debugger for AGS game with command line?
i.e. you run the game, then you type in the debugger smth like SetGlobalInt(5,444);
Display("%d", GetGlobalInt(5) ); and it works in the game
Unfortunately, AGS' scripting language is compiled rather than interpreted, so this would be impossible.
You can probably do something similar with the Lua plugin, though. The Lua script is interpreted.