I enjoy Helmet Heroes for a number of reasons, but one of the glaring differences between HH and other MMO's is not having hotkeys set for easier interface access for smoother and more comfortable gameplay.
Though some of the letter keys are already occupied, maybe using numeric keys (or a mix of alpha and numeric) for quicker access to menus could work. If the F1-12 keys work for this type of flash game, those could be used, as well. Even putting the hotkey setup in such a placement on the keyboard to where it matches the layout lineup on the UI screen (two down, four across).
And maybe down the road a little making the hotkeys available to be adjusted by the player. ^ ^
As an added thought --
Hotbar!
That's right. The good ol' system where you can store a couple/few items where you can have immediate access to your choice of usable item. Whaddya think? Might save a life or two!