I could play it in either mode by the end. I started off in 2D mode, but I kept switching to 3D since it looked so pretty. And by the end of the game I was mostly playing 3D mode, even Hyper Melee mode. Your brain just needs time to adjust. It helps that in the campaign, there’s a lot of easy battles, so you can still do them easily in 3D, even when you’re not used to it yet.