Axu is the most promising freeware roguelike I'm keeping my eyes on. The second closest being Ultima Regum, even if it is more ambitious in scope.
I first came across the game on an "exploration roguelikes" post on reddit. It is still in very early stages and has some bugs and balance issues - but the foundation of the game is so solid, already this early on and has such a great atmosphere that I am fully expecting it to grow into an absolute great title. Matt is also a very cool guy, has a lot of plans regarding the game and a good grasp on what he wants to achieve and seems to be working hard on getting there.
Playing it really feels like going back to the Fallout 1 and 2 games but roguelike style. You won't find deep dialogue trees, moral choices or complex communities in it but it has the same sense of wonder that makes you want to experience the game world. The author hasn't mentioned those games as direct inspirations but the feel is the same for me - and that was more than enough to get me hooked! It really has a rich personality and I want to watch closely how it will mature from a teenage with great potential to a fully realized member of the RL community. The game is currently lacking in quests and late-game objectives (not to mention not having an end game as of yet) but the combat and exploration now are well enough to keep you entertained for a few hours and get to know the game world a bit.
It is also not afraid to break with tradition - good sound design and the small number of keys/actions show that, and that is something I"d like to see more of in the community. There are too many rogue-clones and too few rogue-likes as far as I'm concerned. I believe that pretty much everything that is the core gameplay of Axu is already down on the table (with a few exceptions like global events and more plot) - all this game needs now is more content, some bug fixing and improving on what's already there to become one of the best roguelikes ever made. This is a huge victory, as far as I'm concerned, when there are scores of games out there that have been worked on for far longer but will never break the mold of being too rogue-like for their own good and thus set themselves up for mediocrity, when compared to the major established roguelikes. Here's to hoping that Axu will continue growing in the right direction!
Don't play this game if you're looking for the same exact roguelike experience you've seen in dozens of other games and also don't expect anything close to a full game - but if you're a RL developer like many of us here, make sure to drop by to see how an early project should look like: innovative, charming and unique.