There will be a Dead Space 2 demo hitting the PSN on December 21st.

“In the Dead Space 2 demo, players will take engineer Isaac Clarke on a terrifying adventure through the Church of Unitology, an expectedly “safe” place that quickly becomes dangerous and deadly, during the Necromorph outbreak on the Sprawl. Players will also have access to a variety of new tools that Isaac can use to fight Necromorphs, including the new Javelin gun, updated stasis recharge mechanic and enhanced telekinesis ability. Players will also experience the advanced suit, equipped with jets that will allow Isaac full 3600 control in Zero-G space. ”

This has a lot of potential, and I’m glad they are releasing a demo.
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