"Transistor is a sci-fi themed action RPG that invites you to wield an extraordinary weapon of unknown origin as you fight through a stunning futuristic city. Transistor seamlessly integrates thoughtful strategic planning into a fast-paced action experience, melding responsive gameplay and rich atmospheric storytelling."
83% on Metacritic: http://www.metacritic.com/game/pc/transistor
Totalbiscuit likes it: https://www.youtube.com/watch?v=zymf7o5K9UU
Also Supergiant's previous game, Bastion for £2.19
(which also has a demo):
"Bastion is an action role-playing experience that redefines storytelling in games, with a reactive narrator who marks your every move. Explore more than 40 lush hand-painted environments as you discover the secrets of the Calamity, a surreal catastrophe that shattered the world to pieces. Wield a huge arsenal of upgradeable weapons and battle savage beasts adapted to their new habitat."
86% on Metacritic: http://www.metacritic.com/game/pc/bastion
TotalBiscuit likes it: https://www.youtube.com/watch?v=nyWJhOh7w00