oh you def should keep updating it! Hmmm I probs can come up with a few suggestions:
1. Don't let enemies shoot at the player till they are on screen.
2. Ignore suggestion 1 for a single enemy that is a sniper, have it be off screen and when it is about to shoot the player have a laser appear to show trajectory. Player has to time a parry to knock back the bullet when the laser beam flashes indicating a shot is about to happen.
Those are just some ideas, you don't have to use them if you don't like them, but those would be my suggestions.