At first I thought it was just a shmup but mirrored, but there's actually pretty interesting strategy by playing around the positioning of the powerups and trying to manipulate the enemy's movement into your shots. Maybe it could lean into that angle more by giving you denser bullet arrangements in the available firing patterns so they're more effective as zoning tools. Also, it's definitely unfair that the enemy player can hide off the screen and wrap to the other side.
Great music and visuals too!