Not sure what you mean by style of visuals... especially since you mark textures off the list, which is part of graphics even if just a mesh or skin that is wrapped over a model.
Would I want it to be in 3D or similar, probably not. Terraria is terraria. It is what it is. I am not overly concerned with graphics in general. Would I like to see a 3D or similar version of this game, maybe. But to change the current one is finished and staying; so it is fine the way it is. Lots can be added to it, and already has.
What interests me most is story & entertainment value. Story would be the obvious one, and since Terraria doesn't have much directly as a story... It makes up with hints and overall environment telling the story for it. It is up to the player to decide and lead the story in a way. Entertainment value just means is there something for myself to do in the game that I would enjoy doing.
Since this game offers a lot to do, it makes it easier to be entertained by it. Main thing is the building aspect which I play around with mostly. So changing graphics in any way beyond touchups would seem off for this installment of the game. The art style looks fine. The game play is pretty open, and has many things to enjoy or attempt enjoying, and has an environment to flesh out the world making it pretty lively. I am one that doesn't focus on min/max type of thing, and does my own thing; noting the building aspect. For me that prolongs the game even further since I take my time throughout the game when playing single player. Multiplayer is different matter.
So no, keep it the way it is, and maybe have minor adjustments where needed in the graphics.