Super Kid Icarus is a flash game developed by Flip Industries and uses the keyboard to control user input. See below for information on what actions are assigned to the default keyboard keys. The controls can be changed at any time through the options menu.

Arrow Keys to Move
X Key to Jump
Z Key to Attack
P Key toggles Inventory
O Key toggles Options Menu
If you wish to play Super Kid Icarus with a joypad you could try JoytoKey. Flip Industries and Super Kid Icarus are not associated with JoytoKey in any way.