Most video games use floats. This is because doubles will be emulated in software on some platforms, thus making them incredibly slow. The Unreal Engine, for example uses floats extensively.
Also, most modern x86 processors can perform single-precision operations twice as fast as double-precision, which helps (and saving memory bandwidth is good too.)
On PPC/ARM, single-precision allows you to use Altivec/NEON, which can give significant performance boosts as well.
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Most video games use floats. This is because doubles will be emulated in software on some platforms, thus making them incredibly slow. The Unreal Engine, for example uses floats extensively.
Also, most modern x86 processors can perform single-precision operations twice as fast as double-precision, which helps (and saving memory bandwidth is good too.)
On PPC/ARM, single-precision allows you to use Altivec/NEON, which can give significant performance boosts as well.