Personally, firing in the direction you face is difficult when you get swarmed and want to escape but also farm up. There still seems to be two other pilots, I imagine it would be possible to make the player the copilot to the primary operators of the other tanks that have other aiming controls. Maybe the first tank fires only straight, the second can aim the turret, and the third has multidirectional canons. The waves can get overwhelming pretty fast, while there feel like breaks between them, there could be some relief ship or station for some other minigames to build relations with the pilots and give a way to pause the game.