Lovely Planet (Steam key/Region free).

http://store.steampowered.com/app/298600/
With boots of speed on your feet, an infinite supply of bullets for your semi-automatic and the ability to jump over twice your own height, you´re well equipped to go up against any enemy on your quest to reach Lovely Planet! Balance between jumping around dodging bullets and taking aim for a better shot at your enemies, don´t waste time camping at cover spots and waiting for enemies to pop out - artfully evade the onslaught of bullets and defeat all baddies that stand in your way!

The most authentic First Person Shooter experience, a game of jumping and shooting
Hundred levels to master, five worlds to discover, one faraway destination
Learn and practice each level to earn stars and set world records
Search for multiple secrets hidden deep within each world
Precise Gun Ballet at a flawless 60 frames per second! (conditions apply)
A story so abstract, it´s not told at all - you won´t know what hit you
Original Soundtrack by Calum Bowen