[Kraugh]

no, adrenaline does not wear off in 10-15 seconds. however, balance has to come into play somewhere.

no, it does not make you super human, though it does increase muscle strength (not permanently, of course).

no, it does not give you "full health," but this is the best way to represent nullification of pain.

as for your screen going green, it's just an effect to let you know that you have adrenaline on for gameplay sake. although, it could be paralleled to the tunnel vision that occurs.

it does much more than trigger your "fight or flight" response.