4Four

Story
-------------------------------------------------------------------------------
The plague was released... a vile flesh-eating virus was released on the atmosphere.
Half of the population of the continent has been decimated, and the  rest will sure follow, unless an antidote can be found.
You grab the single containment suit left and a gun, and leave the lab to collect the necessary elements for the antidote...
Gameplay
-------------------------------------------------------------------------------
You start the game on the fields outside the lab. The lab's to the right, and the isotopes have been detected in the underground.
Make your way through the enemies and collect the isotopes before the air in your suit runs out! You have 60 minutes of air. Every enemy that collides with you will rip your suit slightly, docking 1 minute of air. Diving in the toxic underground rivers will drain your air very quickly!
Some air packs may have been forgotten in the cave area, though. Each will give you 10 minutes of air.
Your ray gun starts with 50 shots. Extra ammo boxes may be found in the caves. Each box contains 25 charges.
The Four Isotopes
-------------------------------------------------------------------------------
You need to bring four isotopes to the laboratory for the antidote to be crafted.
They are:
DEUTERIUM (H-2)
ANTIMONY-130 (Sb-130)
IRIDIUM-187 (Ir-187)
THALLIUM-218 (Tl-218)
Items
-------------------------------------------------------------------------------
Four items will help you along your way.
JET BOOTS - Give you an extra boost if you press the jump button just as you start falling.
HIGH PRESSURE HELMET - Helps you to withstand dives into toxic rivers.
BASEMENT KEY - The key to the basement of the laboratory.
BOMB - High powered explosive, can be used to open a path in bedrock.