Voting! Lots of big hitters. Sadly didn't get time to check out Nihilumbra, skyRogue, or Schein.
Papers, Please - Immigration officer simulator set in a cold war era soviet country that does an incredible job in enforcing empathy in you for such a thankless job. Your political philosophy might even change! One of the very few games to do moral choices right through gameplay and player-driven choice rather than through stilted story moments with dialogue options. Whatever your skill level, there'll be an ending for it, and is imminently replayable to get all 20.
Brothers - If you're interested in an emotional game driven by mechanics, this is it. Easy GOTY contender. If you've already played this, do try
Before That Was Yesterday and
Don't Look Back for similar free games with stories told through mechanics.
Neverending Nightmares - Just chills down my spine playing the demo even for a second time. I never thought 2D horror would be this effective. Some excellent scares, top-notch soundscape, and a killer art style. Also,
successfully funded!
Gone Home - The best First Person House Exploration game ever made! I love games where you can find out the story for yourself and this is a really touching (even progressive) tale even if you're not into 90s nostalgia.
Sir, You Are Being Hunted - The quintessential British FPS. The AI is tough, it demands trial-and-error, the weapons are crude for a FPS, and it had me physically shaking as I hid in the long grass from chirping robot hunters accompanied by killer dogs. This could become something special.
Guacamelee! - Possibly the best of the recent metroidvania-style games I've played with a surprisingly fun to master combat system, tough puzzle platforming, and a lovely angular art style. Also, hilarious to boot. If you liked Dust: An Elysian Tail, this is a great step up.
Assault Android Cactus - I don't play many shoot-em-ups because looking at little ships just ain't my thing, so the focus on humanoid protagonists convinced me. I personally love the battery mechanic that works as a timer so you have to be more aggressive in your movement. One of those skill-based games where I want to replay a level to get the best grade. It's also really cute.
Papo & Yo - If you liked Alice Madness Returns with its dark story and 3D platforming (a rarity sadly), this delivers as well if not better on similar themes of child abuse and learning to let go of the traumatic past. Or if you just like wearing loads of goofy looking hats, there's that too. If The Last Guardian never comes out, we still got a good tale here about a child-monster relationship.