hl2 is obvously gonna own halo2. it's got the source engine. i have learned alot aout it from the past few days. ai are so advanced their actions seem scripted, but are not. eevry object has realisitc physics due to the havok engine and source working together. halo2. i dont know much about except it has soem ncie graphix maybe ai improvements, but overall half life2's gonna own it badly.