Thank you! I would totally nerd out over all the ins and outs of late 90's fps graphics if it wouldn't make this reply so long!
As for the feedback I was going to add a lot of sound effects for the enemies as well as some voice acted hurt sfx for the player, but I didn't have enough time, as the deadline was in 2 days and I didn't have any levels completed. The mech actually does take damage, but I didn't really have time to polish it with some sfx either. When it dies it drops the gun, which is what those ammo pickups are for. I was going to add a door that opens when you finished the boss fight, but I was literally hours away from the deadline so I didn't quite end up doing that. I probably should've thought of making the turrets louder so that you know what's hitting you though.