Balanced a few sounds. Added some dropship sounds, as well as a few ones for the attack helicopter.

Some tweaks to the step sounds, since most of them sounded pretty bad.

First introduction of step sounds! Still more to come.

New partial rollermine sounds, all new stunstick sounds.

A little new, experimental step sound for poison headcrabs. New suit and health charger sounds.

Experimental new strider sounds!

Fixed the gravity gun's volume again, added the energy loop sound.

UI Menu Added, tweaked a little the gravity gun's sounds.

Changes to the Gravity Gun and the .357

New .357 sounds, also modified the already existing, firing ones.