'Bullet hell' is one of the best genres, not because I like playing it - liking things is passé - but because it's an exciting example of the way in which a genre and its audience can warp, and focus, and drill down, and close themselves off to outside influence. I find just the existence of Touhou exciting.
If bullet hell was to be picked up and poured back into the wider world of videogames, Tower Of Guns might be what it looks like. Check out the trailer below.
It certainly has a lot of bullets. Tower of Guns also puts a weapon in your hand, and has you fighting through randomised, clockwork-like levels. The randomisation in enemies and powerups is because it's designed to be completed in a single sitting - one or two hours, according to the Steam page - and then re-played multiple times. That sounds like a neat idea to me.
I went for the bullet hell thing, but I could have written the intro to this post from a dozen different angles. Here's another: it's Serious Sam, but with the screaming, heat-seeking enemies replaced with simple artillery. A light, frothy, fast-paced FPS.
Check out the Steam page for more screenshots.