Melissa Explains It All is an open source Omorashi game written in html and javascript. The original game was made by drw. The goal of the game is to have the girl in bed with you while absolutely bursting to pee, while offering lots of interesting scenes along the way.
This game is designed to be run on a webserver. In order to run this offline you need to do this through a localhost webserver. A well-known example of a webserver is Apache. The game is also offered on the following sites:
There is a list of usefull debug functions defined in the "debugFunctions.js" file.
These functions are added to a debug object that can be called from the console when running the game.
I.e. to get all items you can use
Debug.allItems()
To get a list of all functions use Debug.help()