Microsoft featured at its booth a hands-on demonstration of SiN Episodes, the episodic sequel to the eight-year-old futuristic PC shooter SiN. The first episode, Emergence, will be available this spring, with additional episodes coming out every few months. Each episode is expected to cost between $15 and $20 and will provide approximately four to six hours of game content. SiN Episodes uses the Source engine with Havok physics, so objects and bodies will fly and fall realistically. The games feature a dynamic difficulty system that Microsoft claims can adapt to gamers' play styles and skill levels. Microsoft is planning to release SiN Episodes on Xbox Live Marketplace as well later this year, for use on the Xbox 360. A Source version of the original SiN is also planned, but details are sparse.