FREE - Oddworld: Abe's Oddysee [PC] @ Gog

also free on Steam and Humble.

In a lush world of diabolical danger where everyone wants to eat you, you're the skinny guy with no weapons. Run, jump, hide, scramble and talk your way past the ugliest bunch of carnivorous crustaceans ever created. Unlock Abe's special powers, then figure out your foes, and you might save your race. Don't, and you're dinner!

Abe is a first class Mudokon floor-waxer for RuptureFarms. He was catapulted into a life of adventure when he overheard plans by his boss to turn all the Mudokons into Tasty Treats as part of a last-ditch in Molluck the Glukkon's meat-packing empire. During his escape from RuptureFarms, Abe received a vision from the mysterious Big Face, showing Abe that he must not only rescue his fellow Mudokons, but also protect all of Oddworld's creatures from the predatory Magog Cartel.

Enter Oddworld's surreal sensory overload of pure gaming and claim your destiny. Saviour or salami? You decide.

Hungry for more? Check out the Oddworld: Abe's Oddysee editorial

One of the best and most famous platformers of all time
Challenging gameplay, with the odds definitely against you
Great and bizarre graphical design

credit to tf2manu994 @ OZB.