Monkey Madness was a bundle CD sold through the LucasArts website that contained the PC Gamer versions of both The Secret of Monkey Island and Monkey Island 2: LeChuck's Revenge.
The game itself is an old style adventure/puzzle game where you control the main character Guybrush Threepwood. The game is exclusively played via the mouse, which is used to interact with the environment, NPCs, and game items. Not having gotten very far in the game, I can't personally provide an indepth plot summary, however there is a wiki page available at http://en.wikipedia.org/wiki/Monkey_Island_(series).
The game runs directly off the CD and does not contain an installer,
although it does save games to the binary hard-coded folder C:\MONKEY.