Interesting, though very basic.
Would've been nice to have some reason to stop shooting, maybe more movement speed when you ease off the trigger or something. I feel like the barrier player has more say over the overall strategy, so it's a bit sad that both AIs tend to simply target the enemies closest to the line.
Honestly though most issues seem to be in the presentation overall. The game plays fine, the concept's decent enough, it just could've used more punch. The third gun really felt like a downgrade, in terms of enjoyment. It seemed powerful behind the scenes but just didn't feel it, especially after losing the second gun's rapid fire. Every gun sounds the same, and enemies don't really have any visual feedback for if you're hitting them or not. A simple flash or sound cue would've done wonders, even under the time crunch.