The concept is nice but could get some polishing in my opinion.
At the moment I don't see the point in having two players on the stage. My best score was plaing with just one character and ignoring the other. Switching between two characters in a fast action game is not the best choice in my opinion. Maybe make the 2nd character an extension fot the first (like a shoot ability or additional blade for fighting in other directions at the same time) and add a mechanic to loose the second character with getting damage and a mechanic to get it back.
For gameplay the enemys are hard to hit sometimes. You could rework the attack and enemy movement a little bit and since this is on a platform and you can push enemies you could add the possibility to push enemys off the platform. And I think zooming out with the camera so you can see more would also help the gameplay.
The music gets annoying after some time.
As I said: I think the concept is good and could easily be polished to be more fun.
Keep up the good work!