I´m starting up a new project. It´s going to be a web browser game, developed using HTML5, JavaScript and CSS3.

I have some general questions regarding the process of game developing.

1. Should you know everything about your game by the time you start writing the first lines of code? I mean should you know all the details, all the things the player can and can not do? Basically: should you be done writing down new ideas before you begin coding?

2. I understand the pre-production process is about documenting, doing research etc. What does that mean? Does it mean I should open up Word and write down everything about the game? For example what should happen when you click on different things etc.

Thanks for your help!