It's true there's a cool glut but I haven't at all found Diablo III, Torchlight II, Van Helsing and Grim Dawn (early access), for example, to play precisely the same. No more than the 193 first person shooters on the market are "all the same thing." You can have similar gameplay mechanics but entirely different designs on loot, skill trees or lack thereof, enemy spawning, crafting questing, etc.
I dunno if a Gauntlet type game would have much of any of that, actually.
I can't quite tell from the vid if it's a click to move/kill type of game now (per Diablo), or something more like Shadowgrounds, Alien Swarm etc. (keys to move, mousing to aim etc.). Magicka had an unconventional control scheme I never quite got comfortable with, so I'm not sure what to expect.
Couple of my Steam co-op buds who refuse to have anything to do with consoles/handhelds, might at least be keen on this.
Arrowhead would seem to be a natural to do something with the Robotron property later on. They're not a big dev though and I assume Helldivers and Gauntlet are plenty to keep them busy for now.