Don't get me wrong, -- the visuals are acutally pretty neat in their simplicity, it's a matter of the platform. On Steam, I would have suggested that the game will be great despite or even due to the simple and readable visuals, on itch, the genre of the shmups with simple visuals, especially within the free games section, is just a matter of different expectations, which has nothing to do with your game at all. So no change is really needed.
And I really DO NOT think that randomization would do the game a favor, the opposite is the case. I think rather that some sort of additional 'expert mode' run or ... I don't know exactly, just some incentive to play again, whatever it may be. But I wouldn't the change the existing run through the game much for it. I guess, maybe this incentive is actually *not* right. The game does a fantastic job exactly the way it is. It's just a players thing to always *request more* of something that's good the way it is.
So... good job exactly as it is :-)