Achievement Unlocked: Death by sudden appearance
First off, great game. Submitted to games collection, at least one vote from me.
The graphics weren't too shabby, especially since you were going for a retro look. Gameplay is simple, yet challenging. I couldn't tell if the Achievement Unlocked bit was a real concept or a satirical poke at the 360...either way, I felt it was unnecessary. But then, that's how I feel about Achievements on the Xbox too.
The only thing I think could use some serious improvement is the death aspect. I died twice, in rather quick succession, because the orb suddenly reappears. Perhaps have it start out small and grow, giving the player a chance to adjust to it being there. Rather than having a slightly-difficult-to-predict time frame before it pops back at full size. By the time the walls are coming fast and cramped enough for a player to die, they're coming so fast that there's no reaction time to avoid getting killed again.
Good game though...fully deserving of front page, imho.