The trend in improved graphics continued well into the next release, "Age of Empires III," much to the delight of reviewers. IGN stated, "After seeing the screenshots, our jaws hit the floor at the amount of detail." "1UP.com" described "Age of Empires III" as "one of the most beautiful games you will put on your computer for the foreseeable future." GameSpy agreed, stating, ""Age III"s graphics are unmatched in the strategy genre." "Age of Empires III" builds on and introduces new features to the prior release, "Age of Mythology," such as the inclusion of the award-winning Havok physics simulation middleware game engine for the Windows version and PhysX for the Mac OS X. The innovative result is that pre-created animations are avoided; instead events are calculated according to the physics engine. Consequently, views of events like building destruction and tree felling are not pre-recorded. GameSpot also admired the graphics in the fourth release but complained about "the awkward unit behavior." Other graphical features of the game include bloom lighting and support for pixel shader 3.0.