How did you pick the font? I find myself having problems figuring out is a single letter is a l or an i or a j sometimes. Seems like there's a lot of fonts out there with better readability.
Ideas:
> Smaller words protected by a "forcefield" of a bigger word.
> Wrong letter halfway through spelling could make the enemy ship shoot a "backspace" torpedo that can only be destroyed with the backspace key. So three wrong letters would shoot 3 backspace torpedoes at you.
> Two long words reaching out could a tractor beam.
Also, thanks for a surprisingly entertaining, and maybe even useful game :)