Recommendations for PC Twin-Stick Shooters?

I’m looking for any twin-stick shooters on the PC. By twin-stick I mean a top-down game where firing is independent of facing, so it can either literally use the twin sticks on a gamepad or keyboard for movement and mouse for firing, or maybe some other control scheme I haven’t run into yet. Beat Hazard is a big one, as is Alien Swarm, though Steel Storm wouldn’t be one because the player ship always fires forward.

Besides those two, any other good ones? If it’s on Steam, that’s a plus, but it doesn’t need to be. Thanks!

Ion Assault fits the bill. It’s got a clever little scoring system that gives it a bit of life as a hybrid shmup/puzzle game.

On the PC, everything in that subgenre of shoot’em ups is compared to Crimsonland 'cause it’s the best.

Crimsonland is on the oldschool side of things, with more RNG weight to it with regards to item & weapon drops than is really healthy in a shmup. The giant weapon list is fun, though if you’re going back to old style gameplay you may as well go whole hog and hit up Robotron or Smash TV on an emulator.

Just remembered Burn Zombie Burn, done up in a B-grade horror theme complete with a Bruce Campbell clone main character. The scoring is a fairly intuitive risk/reward scheme where setting zombies on fire builds up a multiplier until they burn to death, but also makes them move faster.

Good call on these. I forgot to mention in the OP, do any do co-op?