I develop this prototype with Javascript. This language doesn’t support game pad events. But some alternative solutions exist.
Some free softwares convert game pad input to keyboard input. When you press a button on the game pad your computer and your browser believe you type key on your keyboard.
You have to edit some settings in the software so that it knows what button and what key are linked.
Nowadays, most game pads have 10 buttons, 4 arrow buttons and 2 sticks, so my game needs arrow keys and no more than 10 others keys. The ones of you who prefer use keyboard and mouse will can program additionnal keys, but it will be only an option and not necessary to play the game.
Here is some softwares for example :