With its gameplay inspired by the likes of Sworcery and rhythm games, Deepest Dungeons of Doom looks to be a rather interesting offering. A work-in-progress by Miniboss, Deepest Dungeons currently only requires you to make use of three buttons so as to be able to attack, defend and use items. Coincidentally, it only has three classes too. Sadly, the developers haven't made any recent updates in regards to the game so I'm clueless as to how far it's progressed.

Still, if you're interested in keeping watch over its development, here's the appropriate TIGsource forum thread.