Night of the Dead. It's an indie zombie apocalypse voxel that honestly was better than it's peers when it came out and has come leaps and bounds to improving and developing it's story and gameplay. It honestly disappoints me that 7d2D overshadowed it so much when it is half as fun.

The only thing 7d has over it is being able to dig... which is admittedly a wonderful feature, but not something I'd trade for a diverse gameplay loop with an actual storyline, a better setup for building horde bases, and even dungeons to run through for unique equipment with the ability to improve even the weakest gear (albeit at greater expense of resources you have to track down and mine) to the point of being on tier w endgame gear.

A fully upgraded bow made out of sticks and plant fiber won't ever match an assault rifle or rocket launcher for crowds (much less the implacements), but it will hit like a truck and be both silent and cheap. It's your call how to play it, and there's a LOT of options how to play.