Mthdia beat me to it. If you log out and back into Steam the game is now available. Also, the game is available with the OnLive service. We'll have a patch soon that supports window mode. @ae, Stats page has a breakdown of how your earned the skulls.
just complete-completed it (all the skulls on nightmare). 6 times the play time of 'game of the year' Portal 2 for a third of the price, and i will keep coming back, unlike the aforementioned. If this one doesn't get recognised in the yearly round ups, somethings badly wrong. Solid round of applause please for Robot…
Played it during the weekend so fun, my only gripe is i don't know what factors in to get more skulls? sometime the orcs don't even get past my beginning defenses but i still get two stars. or sometimes i think ive done horrible but i get 5 stars it really confuses me.