Lone Ruin
Lone Ruin may be difficult and short, but it's a roguelike worth digging into if you want to climb the leaderboards with some awesome spells and dynamic gameplay.
Voidigo
At the end of semiwork's promotional video, the tagline is, "One last try, again and again," which should work for every great roguelike title. This genre predicates itself on killing a player again and again but keeping them coming back for more. Voidigo follows this thought faithfully. You're going to want to keep coming back for one last try.