Yesterday during Sega's iPhone Games Day, easily the most impressive and fun game that I had a chance to play was Sonic 4. It finally feels like the Sonic game that we've all been wanting for the past 15 years, with no gimmicks, unnecessary characters or outlandish stories. Just pure 2D side-scrolling Sonic goodness, with heaps of Blast Processing. We previewed Sonic 4 during E3 in June, where we had a chance to play an early version of the game. Yesterday at Sega I was shown a nearly complete build of the game that included the previously unannounced Labyrinth Zone, two exclusive iPhone levels, and the special Chaos Emerald bonus stages.