Update coming soon.

Things completed in the update:

Invincibility Pickup (not only gives you invincibility for a short time, but zombie attacks HEAL you while invincible. Rare pickup.)

Pickups now flash when they are about to disappear.

Slight modification to the rarity of a machinegun pickup. When I played my full round, after building up over 2500 bullets for the machinegun and not being able to get rid of them faster than I could find them, I figured I should balance this out. I may also implement a maximum ammo capacity.

Working on:

Hit "zones." Instead of checking every bullet against every zombie to see if there's a hit, the bullet will now only check zombies within the "zone" it is in. I'm working out the bugs on zombies standing on a borderline between two zones, where a hit doesn't register, and the lag induced by having many zombies onscreen with this setup. However, bullet updates don't seem to affect performance so much now :D