Joe Mirabello of mostly-one-man studio Terrible Posture Games really seems to like guns. In 2014 he released the twitch-FPS Tower of Guns, and today he revealed the follow-up, Mothergunship, a bullet hell/FPS hybrid that pits you and your "very, very big" guns against hordes of robotic alien invaders.
You can see from the trailer that the action in Mothergunship is a little different from conventional FPS gameplay, because you actually have to dodge incoming fire. Projectiles move much more slowly than they do in conventional shooters, but there are an awful lot of them, and while it's not stated explicitly I would guess that you're not going to be able to tank through them like you mostly can in Doom.
Players will be able to build their own unique weapons using "one of the most modular gun-crafting systems ever seen in a videogame." And there will be multiplayer support, although it's not entirely clear how that will work: The announcement says only that you can "fight together with a friend in a full co-op experience, or participate with the community while you work together to cut through the alien fleet and reach that ultimate goal—bringing down the Mothergunship."
It looks great, although also very much like the sort of game I probably won't have the patience to play in any meaningful way. I'm an FPS killer going way back, but bullet hells are a very different story. Then again, I've never had to take one on from a first-person perspective, so maybe it'll work out. Either way, I'm looking forward to giving this a shot when the opportunity arises. Mothergunship doesn't have a release date yet, but it does have a website you can poke through at mothergunship.com.