Circle menu

Considered by Halo Wars's Lead Designer, Greame Devine, as probably the most important menu the the game. So large that the menu itself takes up the whole screen. It is used from, to qoute the L.D, "... for everything. To building infantry, to building vehicles, to building buildings and for calling in Leader Powers" The player can navigate through the Circle Menu via the Analog Joystick, to select whatever he/she so chooses

Source
http://forums.halowars.com/forums/1/91352/ShowThread.aspx#91352