Quantum Conundrum (66% Off)

Retailer: Greenman Gaming

Price: $5.09 (66% Off)

Link: http://bit.ly/TImm27 

If you've been waiting for another Portal game, we've got the next best thing for you on sale this week. Quantum Conundrum was made by Kim Swift, one of Portal's creators, and is every bit as clever as its predecessor. You'll switch between multiple realities to solve puzzles and rescue your mad scientist of an uncle.

Don't forget, you can use the code GMG20-1FYLZ-EDG8R on checkout to save an additional 20% off your purchase.