The Game Collection are selling "Archer MacLean's Mercury" for £4.00 (inc Del.)
The next best price seems to be £8.93 from The Hut.
Created by Archer MacLean, Mercury puts you in control of ultra realistic liquid mercury which you have to steer through 72 levels spread over six challenging worlds. Using your brain and balance, control the mercury around various obstacles and puzzling scenarios as well as keeping everything intact.
Blob control is important; keeping your liquid mercury together and not spilling is the key to completing your goal as well as identifying the colours you need to move through certain areas. Once you've achieved your goal you'll face the end of level boss who won't
be a walk in the park. Can you handle the challenge?