1.
XenoRaptor
Now true, the game isn't even finished yet, and it may not have the depth of a game like Crimsonland, but I believe how fun a game's gameplay is, how enjoyable its mechanics are is paramount, and I can't stop playing XenoRaptor. Its a game I keep returning to, because I find the mechanics and gameplay so enjoyable. It's fast and fluid, with vivid stylishly weapons, and agile responsive controls. Similar to how Teleglitch's distortion effect made your weapons seem like they were tearing apart the environment itself, the small effects - from the screen shake, subtle zoom, recoil, etc. - make every one of XenoRaptor's weapons feel satisfyingly powerful. Evading a swarm of enemies, watching them kill eachother, and then wiping out the stragglers with your lightning shotgun is just awesome.
2.
The Floor is Jelly
On the surface, The Floor Is Jelly is a standard platformer, run and jump over gaps, and dangerous spikes, wall-jump up narrow tunnels. The controls are responsive and simple. On that note, it isn't the most challenging game, certainly not in the spectrum of difficulty of games like Super Meat Boy or even Braid. But those points aren't negatives; The Floor Is Jelly is a fun game, and the difficulty comes not from frustrating challenge but from the gradual layering of new interesting puzzle mechanics. From flowers that bloom in rain and those only sprout without rain (because they're part cat of course) to switches that rotate entire levels, and then switches that rotate only singular platforms, and later Guacamelee-style dimension swapping, The Floor Is Jelly constantly introduces new mechanics that add to the core gameplay in fun ways. The endlessly entertaining and charming art style only adds to the enjoyment.
3.
LYNE
While LYNE is also available on PC, I'm convinced that the best way to play it is on a touchscreen. The smooth minimal interface hides a massive wealth of content. The puzzle mechanics themselves are simple - connect various paths between nodes - but the infinite levels and the increasingly challenging puzzles make it an enjoyable addictive experience.
4.
Turbo Dismount
Turbo Dismount won't appeal to everyone. Some will think it's simple and boring. And true, the game is mechanically simple, but as a fan of the original freeware Dismount games and Stair Dismount on IOS, I never find Turbo Dismount. Take Burnout's Crash mode and add a fragile easily dismembered ragdoll and then mix in all kinds of obstacles and vehicles and you have Turbo Dismount in a nutshell. It's the kind of game you play to watch the crazy replays in slow motion, watching your vehicle tumble and your ragdoll get torn in half by a bus. The regular updates and active developers make the experience even better.
5.
Olympia Rising
At the moment, Olympia Rising is only a demo, a snapshot of what the full game will, but that sliver of gameplay is already fun and polished, with nice pixel graphics and fluid challenging gameplay that puts a focus precision and flow, I almost overlooked this game but the demo sold me. I can't wait to see how the game grows and evolves in the months to come
---
Kromaia - been supporting this game a while, since its Indiegogo campaign. It's fast-paced, visually impressive, 6DOF twitch combat in open abstract environments and with great music. The alpha is kind of bare bones, but it's very promising and the core gameplay is already polished and fun.
Rockets Fucking Everywhere - The title says it all. There are rockets fucking everywhere and you need to dodge them. It's the kind of game that could easily be lost even among the most niche of indies, but RFE does one thing - insanely fast, very challenging twitch evasion - and it does well. And bonus points for the great name
Nidhogg - Chunky pixels fighters in weird environments, that has more depth and strategy than you might expect at first glance. The tense seconds as you and your opponent size each other up, the fast furious combat with its nice animations and wide range of moves, and the varied arenas make Nidhogg a joy to play
Hyphen - Loved the demo, and how the developers added more arcadey style obstacles and hazards to the already challenging Kuru Kuru gameplay
Trace Vector - Surprisingly addictive and challenging, the simple controls make for a simple to play, tough to master twitch game of reflex and reaction.
Zenzizenzic - Promising abstract bullet hell shooter that is definitely art in motion.