Votes:
1. Factorio
This game swallowed about 15 hours of my time and considering the upcoming updates, no end in sight. The combination of SpaceChem like optimisation for a factory setup in an open world is just way too fun to mess around with. This game is currently in v0.2.10 and I can already guarantee that it will land in my GOTY list.
2. Gorogoa
This game is a celebration of creativity and imagination. Its lovely, intelligent, interesting, thoughtful and most of all blurs the line between interactive storytelling and videogames. The game clearly has adventure like puzzles to push the story forward, but at the same time it employs some mechanics that are so "unvideogame-y" that people can just view it as a toy to play around with and be amazed.
3. Starseed Pilgrim
Considering this game singlehandedly restored my faith in games, I am probably not giving it enough attention. The idea of starting a game where the first part of the game is to explore the mechanics was so damn refreshing and rewarding. This game was a throwback to 10 year old me, first dabbling into videogames again, where everything was new and exciting. It showed me that my "curiosity" isnt gone, its just not provoked by most 'AAA' games anymore due to lack of everything that can make videogames so special.
4. Papers, please
Fantastic concept and how it represents dealing with a rather monotonous task that changes lives is just plain amazing. I also enjoyed the detective work at work here, but this game deserves recognition for its setting and the implication the depicted work provokes. The game is not fully fleshed out yet, but this will be a game many people will enjoy and love. Hail to Arstotzka!
5. The Sea Will Claim Everything
These games seem "childish" due to their simple looking nature, but they are actually highly interesting games. A reviewer put it like this. "This game seems to be made by a 5 year old that read Nietzsche", which kinda hits the mark. There are so many interesting and thoughtful jokes,puns and references in here, that its just a blast to go through this game and read about these. It also doesnt hurt that its actually a capable adventure game too, but the real star of the show is the intelligent and fun use of references. A delight to play.
Honorable mentions:
Maldita Castle - I think this game got a bit too late into the thread, but its a FANTASTIC 2D ghost and goblins type game. It looks great, plays great and is just a perfect throwback to those days. In a not so busy month, this could have landed in my top 5 as well.
Zineth - Fantastic sense of speed and exploration. Very, very, very well executed game. More people should give it a whirl (especially since its free)
Underrail - Its 2D Fallout! It ALMOST made my top 5. They have branching dialogue trees, quirkiness and everything that made the 2D Fallouts fun. This game would have gotten a thread from me, but I notice someone else already did one.
Kentucky Route Zero - Its a bit too expensive, but its a very well made adventure game. The style is plain awesome and the story and meaningful player interaction caught me off guard completely. If more people get to play it (50% steam sale), this game will be considered a classic by many.