One thing I completely forgot to mention are the Chimeran cores, batteries where the Chimera store energy. If I'm remembering right, there are three cores in stored in a rack, and each core is ball-shaped. Scattered throughtout the levels, they're essentially next-gen exploding barrels.
But they're not static and boring like exploding barrels. Depending on which core you shoot, top, middle, or bottom, the other cores react appropriately to the explosion and go flying off in whatever direction before exploding. It's a cool touch, both in terms of gameplay (intelligent use of the cores can be helpful) and atmosphere (accidently nail a core during a firefight, cores go flying, explosions are everywhere, things get way more chaotic).
